PsychonomicBulletin & Raiqt r996, 5 (1),5670 Is agekinder to femalesthan to males? FLITABE IH J. MEINZ and TIMOIHY A SALiTHOUSE Geuryia Insntuuof Tuh,rwlqg, Atlanta., GwVi/a Psychonomic Bulletin & Review 1998, s (1),s6-70 Is age kinder to femalesthan to males? EUZABETH J. MEINZ and TIMOTHY A. SALITHOUSE Georgia Institute of Technolngy,AAnntn, Georgia To investigate possible gender differences in the patterns of age-cognition relations, a metaanalysirswas conducted on the data from 25 studies (5,201 participants) by the second author and his collaborators. Gender and age differences consistent with prior reports were found, but there were few measures on which the age x gender interactions were significant. Although the mqiority of neuroimaging studies investigating gender differences in age-related atrophy and functional de cline report greater age-related differences in males, the only significant interactions on the cognitive measures in this study (on mea^suresof speed and reasoning) were in the direction of lesser agerelated declines for males than for females. Age-related differenceshave been reported on various measuresof cognitive functioning, frequently in the direction of lower levels of perfornance with increasedage (for reviews,seeBlanchard-Fields& Hess, 1996,and Craik & Salthouse,1992). Gender-cognition relations are also well documented, with higher performance in males on some measures,such as spatial abilities, and higher performancein femaleson others,suchas verbal abilities (for reviews,seeHalpern, 1992,andMaccoby & Jacklin,1974). Although this pattern of gender--cognitionrelations reportedly remainsrelatively stableacrossage (Schaie, 1996F for example,the male advantagein spatial abilities is evidentthroughoutthelifespan(Willis & Schaie,l988fthe interrelations among age, gender,and cognition have received little attention. In other words, although the qualitative pattern of gender diffbrences in performance may remain stableacrossthe lifespan,it is not yet clear whether the quantitative relations between age and cognitive performance are the samefor femalesand males.An interaction ofage and gendermight be expectedin light ofrecent reports of gender differencesin age-relateddecline on some measuresof brain morphology and functioning. For example,Gur et al. (1991) reportedthat, although men and women showedsimilar patternsof age-related decline in brain volume, there was a significant interaction of age and gender on another measureof brain atrophy, cerebral spinal fluid volume (CSF). Men showed greaterage-relatedincreasesin CSF than did women, suggesting more pronounced atrophy with advancing age in malesthan in females.Interactionsof ageand genderwere also found in ratios of ventricular to sulcal volume because therewas no gendereffect in the rate ofventricular atrophy, but men had greater age-relatedsulcal atrophy than did This researchwas supportedby NIA Training Grant AG00l75 to E.J.M. and NIA Grant R37 6826 to T.A.S. The authors gratefully acknowledge the helpful comments of Paul Verhaeghen,Diane Halpem, David Lane, Lars-Gtiran Nilsson, and one anonymousreviewer. Correspondenceshould be addressedto E. J. Meinz, School of Psychology, Georgia Institute of Technology, Atlanta, GA 30309 (e-mail: gt4956b @acme.gatech.edu). Copyright 1998PsychonomicSociety,Inc. women. There were also gender differences in the hemispheric patterns of age-related atrophy; women showed similar atrophy acrossthe hemispheres,but men showed greater atrophy in the left ventricles than in the right ventricles. The first two findings, that of larger increaseswith agein maleson overallCSF and sulcalCSF,suggestgreater age-relatedbrain ahophy in men than in women, and the third finding indicatesthat malesshow greaterage-related decline in left hemispherestructuresbut not right hemispherestructures. Kaye, DeCarli, Luxenberg,and Rapoport (1992) also found that the onset oflarge age-relateddeclines in brain volume occurred earlier in men (beginning in the 1950s) than in women (beginningin the 1960s).Additionally, gender differencesin the relation ofage to brain changeshave beenfound with femalesexhibiting smaller declinesin the caudate nucleus and putamen (Raz, Torres, & Acker, 1995),and in whole brain, frontal, and temporal lobe volume (Cowell et al., 1994; Murphy et al., 1996). However, males showedless age-relatedloss of hippocampaland parietal volume (Murphy et al., 1996). A few studieshave usedmeasuresof brain functioning rather than structurewhen investigatingage-gender relations. In measuresof slow electrophysiological activity, Duffy, McAnulty, and Albert (1993) found greateragerelated activity reductionsin men than in women. Gender differencesin the relation of age to measuresof brain metabolism havealso beenreported, with greatermetabolic declinesin the left hemispheresthan in the right hemispheres of men, but either greater metabolic decline in the right hemispheresor equal metabolic decline acrossthe hemispheresin women(Murphy et al., 1996).Theseresultsare consistentwith the structuralfindings of Gur et al. ( l99l ), and they extendthem with functional evidence. Although the precedingstudiesprovide fairly strongevidence for age-gender interactions in brain structure and function, severalauthorshave noted that it is desirableto determine whether similar interactions exist with behavioral data(e.g.,Cowell et al., 1994;Gur et al., I 991; Raz et al., 1995).Isolatedstudieshaveinvestigatedthe effects of gender on age-cognition relations with specific cogni- 56 IS AGE KINDER? Table I oflncluded 57 Studles Age Males 4 ) 6 7 8 9 t0 ll l2 l3 l4 l5 l6 l7 l8 19 20 1t )) z) 24 25 26 202 218 195 128 221 228 223 100 305 240 l?{ 246 258 I ts I l'l t78 227 t11 l3l 259 l9'l 139 zJ) 242 383 2,411 59 9l 86 43 86 t25 ll0 53 124 8'l 60 95 102 8l 57 6l lil 94 80 95 83 58 108 r02 186 1,129 Females M 143 127 109 85 54.6 53.3 5l.5 46.1 48.5 50.3 49.2 45.0 51.1 48.l 51.5 46.6 48.7 46.5 49.0 49.0 50.7 46.9 46.1 51.4 49.6 47.7 48.5 49.1 46.0 36.8 r35 103 ll3 47 181 153 65 151 r56 92 60 lt7 l16 139 5l 164 lt4 'tl 125 140 t97 t,282 S D Citation 18.3 14.0 15.7 15.6 17.4 17.7 17.6 l'7.4 16.6 15.9 16.5 t7.0 17.0 19.6 16.4 20.1 r 6.8 16.4 20.0 18.4 17.4 16.4 17.3 t7.5 l6.8 19.6 tive or neurbpsychologicaltests. For instance, in one of three verbal memory tests,Larrabeeand Crook (1993) found a significant interactionofage and gender,suchthat females showed less age-relateddecline than did males, but, in an earlier study, no significant interactions were found on thesetypes oftests (Larrabee, Trahan. Curtiss. & Levin, 1988).In a studyby Elias, Robbins,Walter,and Schultz(1993), a largebattery ofneuropsychologicaltests was administered,but a significant interaction of age and gender was found only on the Halstead-Reitan category subtest.lnteractions ofage and genderwere testedin a study of gender-relatedepisodic and semantic memory diffe;encesby Herlitz, Nilsson, and Bdckman (1997\, but no significant interactionswere found. Schaie (1996) summarizedthe findings of the Seattle longitudinal study,stating age-difference patternsappeargenerallyinvariantacross sexwithindomains(albeitthereis strongevidence for overall genderdifferences in levelofperformance), but it is not a foregoneconclusionthat suchinvarianceholds for all abilitiesor for all markersof a givenability.(p. 83) This statementimplies that more thorough investigations of the interrelationsamong age,gender,and cognitiveperformance are needed. The purposeofthe presentstudy was to conduct such a systematicinvestigation using meta-analyticprocedures. However, becausethe requisite information for a metaanalysisof this type (i.e., effect sizeestimatesfor the age X gender interaction) is seldom reported, the present Hambrick,Salthouse, &Meinz (1997,Studyl) Hambrick,Salthouse, & Meiw (1997, Study2) Hambrick,Salthouse, & Meinz(1997,Study3) (1998) Meinz& Salthouse (1991,Study1) Salthouse (1991,Study2) Salthouse (1991,Study3) Salthouse (1992) Salthouse (1993) Salthouse (1994a,Studyl) Salthouse (1994a,Study2) Salthouse (1994b,Studyl) Salthouse (1994b,Study2) Salthouse (1995a) Salthouse (1995b,Srudy2) Salthouse ( I 996) Salthouse Salthouse & Babcock(1991, Srudyl) Salthouse (1991,Study2) & Babcock Salthouse, Fristoe,Lineweaver, & Coon(1995) Salthouse, Fristoe,& Rhee(1996) Salthouse, Hancock,Meira, & Hambrick(1996) Salthouse, Kausler,& Saults(1988,Studyl) Salthouse, Kausler,& Saults(1988,Study2) Salthouse & Meinz(1995) Salthouse & Mitchell(1990) Woodcock-Johnson standardizationdata analyses arebasedon rawdatafrom studiesconducted bv T.A. Salthouse andhiscollaborators overthepastI 0 years. METHOD Selection ofStudies The primary analysisfocusedon raw datafrom 25 cross-sectional studiesconductedby T. A. Salthouseand his collaborators.All of these sfudiesincludedboth male and femaleparticipantsof a continuous age range.Participantsin all ofthe studieswere recruited through newspaperads, community groups, or personalcontacts, and no specialappealsweremadein the studiesto eitherfemalesor males.To the bestofour knowledge,noneofthese individualsparticipatedin morethanoneofthe includedstudies.performancemeasuresiiom all ofthe cognitive variablesin thesestudieswere included. There were a total of 5,201 participantsand 74 diferent variablesacrossthesestudies.Although this wasnot a typical metaanalysis(for the reasonsdescribedearlier),the resultsofthe analyses should be broadly generalizablebecausethe age relations in thesedatahavebeenfound to be similar to thosereportedbv other investigators (i.e.,Verhaeghen & Salthouse, 1997). Data from the most recent standardizationof the Woodcock_ Johnsontest battery(Woodcock& Johnson,1989,1990)were also includedin a separateanalysisto be comparedwith the resultsofthe primary analysis.I Data on 35 variablesfrom 2,41I participantsbetween 18 and 94 yearsofage were availablein this data set.Characteristicsofthe participantsfrom eachofthe studies,includingage and genderdistributions,arereportedin Table l. Classification of the Tasks All taskswereclassifiedasoneofeight types:speed,spatial,primary memory/workingmemory, episodic memory, reasoning, knowledge,verbalfluency,andmiscellaneous. Briefdescriptions;f all tasksincludedin the meta-analysisare listed by task classifica- MEINZ AND SALTHOUSE 58 to Gender & Io r o : f.o lr n -t -.0 -.6 -.4 -2 2 .1 .6 .8 t.0 to Age c) 9.0 E f.o lt n -1 -.8 -.8 10 -2 2 .1 .6 .E 1 . 0 GenderDtfference 80 9 g.0 E.o lr n -1 -.8 -.6 -.4 -2 0 2 .1 .6 .8 1.0 Figure 1. Gender, age,and gender differcnce in age-correlation effect-sizefrequenciesfor ell variables in the primary studies. Note that the observationsare not independentbecausethe correlations are based on individual variables, and, thus, several mersunesof the ssme task classification may be included from a single study. A total of 240 correlations are included in eech distribution. tion in AppendixA. Theseclassificationswerechosenbecausethey representdistinct categoriesofcognitive taskswith differing levels of age-performancerelations.Although classificationby type of stimulusmaterial(i.e., verbal, spatial,numerical,etc.) is also a viable option (becausegenderdifferenceshave been studiedusing theseclassifications),it wasdecidedthat this levelofanalysismight be more appropriatefor homogeneityanalysesif, in fact, heterogeneitywithin the classificationswas found. dataweregroupedin The variablesfiom the Woodcock-Johnson a similar mannerandaccordingto the abilitiesthat the tasksarepurDortedto measurewheneverpossible. Procedure Effect sizes.Following the suggestionofRosenthal (1991),the Pearsonproduct-momentcorrelationcoefficient,r, was chosenasa measureofeffect sizein theseanalyses.All variableswerescaledso that higher scoresindicatedhigher levelsofperformance, and, therefore, negativecorrelationswith age indicatedage-relateddecline' Genderwascodedsuchthat maleswereassignedscoresofO andfepositivegenderefmaleswere assignedscoresof l; consequently, fectsindicatehigherlevelsofperformancein females,andnegative gendereffectsindicatehigher levelsofperformancein males. To expressthe age x genderinteractionas an effect size, a differencescorewas computedbetweenthe age effect sizes for males and for females by first converting eachage correlation to a Fisher z, subtractingthesezs, and then convertingthe z6.i6backto an r6i6.2 Effect sizesfor femalesweresubtractedfrom thosefor males;thus, a negativevalue indicatesgreaterage-relateddeclinein malesthan in females,anda positivevalueindicatesgreaterage-relateddecline in femalesthan in males.To illustrate,if the ageeffecton a variable was -.6 for malesand - .4 for females,166 is equalto the z transformationof the male effect size(-.69) minusthe z transformation of the femaleeffectsize( - .42),which is equalto - .27.When convertedback into the correlation metric, this negativedifference score (ra;6: -.26) indicatesgreaterdeclineamongmalesthan females'3 For illustrativepurposes,the distributionsofeflect sizesfor gender, age,andthegenderdifferencein ageconelationsacrossall variables (N :240) areshownin Figure I . It shouldbe notedthat the rangeof effectsizesin thesehistogramsis relativelynarrowandthat only the distributionof effect sizesfor agewas not centeredat zero. thatwould resultfrom In orderto avoidthe stochasticdependence using severalindicesof one cognitiveability from the samestudy and the sameparticipants,a singleeffect sizemeasurewas derived for eachstudy in a given task classification.For instance,for each studythat includedtasksclassifiedasmeasuringspeed,only oneeffect sizewasusedin the analyses,regardlessof whetherthe particular study included I or l0 speedvariables.To obtain this average effectsize,theeffectsizesfor eachtaskweretransformedvia Fisher's r-to-z transformation,and then the zs were averagedto yield a z*-*". Finally,thez**" wasconvertedbacktoaneffectsizemeasure(r*op. The averageefFectsizesfor the studiesin the primary analysisare listed in AppendixB. Etfect size estimation. Mean weightedeffect sizes (r+) were computedacrossstudiesfor gender,age,and the age x genderinteractionterm for eachtask classification.Theseweightedcoefficientsandtheir 950%confidenceintervalswerecomputedby assigning weightsto eachstudyon the basisof samplesizes,asdescribed in Rosenthal(1991)and in HedgesandOlkin (1985).Weightedeffect sizeestimatesandconfidenceintervalsfor eachtaskclassification in the primary analysisarepresentedin Table2. Testsfor homogeneityof effect sizeswithin the task classifications werealsoperlormedby computingQ1, a measureof total homogeneity,andcomparingthis valueto the critical valueestablished by the chi-squaredistribution.Ifthe effect sizeestimatesare found (i.e., ifpl exceedsthe critical value),moderato be heterogeneous tors may be tested.Successfulmoderatorsare thosethat yield hobetweenwithin-groupvariance,pvy,andheterogeneous mogeneous group variance,Qs. For instance,if p1 revealsheterogeneityin the measureof speed,the taskmediummay be identified as a potential and moderator,andthe group may be divided into paper-and-pencil computerizedtasks.The goal of subsequentanalyseswould be to dernonstratethat therewassignificant variancebetweenthe moderator groups(p/, but therewas little variancewithin eachof the groups (Q* for paper-and-penciltasks and p1ryfor computerizedtasks). WoodcockJohnson Analyses Age, gender,andage x genderinteractioneffectsizeswerecomputed for eachtask in the Woodcock-Johnsondata. Theseeffect sizeswereaveragedwithin taskclassificationsto producemeaneffect sizesthat could be comparedwith the weightedmeaneffect IS AGE KINDER? 59 Table 2 Mean Weighted Correlatlons,95To Confldence Intervalg and Homogeneity Stetistics for Thsk Classiflcatlons in the Primarv Anelvsis TaskType Eflect N r+ LLNL Q, 4,99 Speed Gender Age Male Female Gender difierence 2,585 Spatial Gender Age Male Female Gender difference Primary/Workingmemory l4 2.632 Gender Age Male Female Gender difference Episodicmemory 12 -.18 -.36 -.35 -.36 .01 -.22/-.14 -.39t-.32 - .381-.32 -.401-.33 -.02/.05 11.7 6 24.83t 57.00* 28.50* 50.45r M>F Y>O -.07 -.39 -.39 -.39 .00 -.1l/-.03 -.42/-.35 -.42/-.36 -.42/-.36 -.04/.04 4.46 33.61| 44.90r 46.73* 40.43* M>F Y>O .03 -.35 -.36 -.0|.07 - .39t-.32 -.39t-.t2 - .4lt- .i4 -.02t.06 20.42* 26.1V 39-44' 32.40* 26.27' n.s. Y>O - -09t-.02 - . 4 1 / -. 3 5 -.38t*.22 -.44/-.38 .03/.1 l 10.73 77.44t 148.60* 48.99* '16.5t+ M>F Y>O .02 2,97| Gender Age Male Female Gender difference -.05 -.38 -.J) -.41 .07 r,380 Gender Age Male Female Gender difference Verbal fluency 29.28 80.68r l3l.l0r 82.60r 7f .61; -)t l2 Knowledge .02/.0'l -.53/-.48 * .51/-.47 -.54/-.50 .02/.07 2,460 Gender Age Male Female Gender difference Reasoning .04 -.50 -.49 -.52 .05 -.04 n.s. n.s. n.s. Fv)o)Mv)o n,s. o>Y .23 .00 l.7t 2l .00* 36.'t51 10.83 18.59r .M -.03 -.o4 -.02 -.02 - .04/.t2 -. l 1i.05 -.t2/.04 -. I 0/-.06 -. l 0/.07 4.21 1937r 46.95* I 1.83i 18.49* n.s. n.s. .0'l -.39 -.38 -.40 .03 .0r/.13 - .44t- .J4 - .431-.t2 - . 4 4 1 .-3 5 -.03/.09 3.13 6'7.15r 86.92* 56.92x 1 0 . 2+1 F>M Y>O -z) 598 Miscellaneous Fy)o)My)o -.09/.02 .t8t.28 .18/.28 .r8/.28 -.05/.05 .z) Gender Age Male Female Gender difference F>M Y>O n.s. n.s. I,082 Gender Age Male Female Gender difference n.s. Note-Task type is the task classification formed fiom variables believed to measurea common cognitive abllity; ellect refersto the type of effect reported; *, number of studies included in analysis; N, number of participants included in analysis; r+, mean weighted correlation; LLfuL, lower and upper limits of 95% confidence interval; Qr,total homogeneity; n.s., nonsignificant; F>M, significantly higher performance in females than in males; M>F, significantly higher perfiormancein males than in females; Y>O, significantly higher performance in young participants than in older participants; F )o)M">o, significantly greater age-relateddecline in females than in males. *p. .05 (nonhomogeneity). sizesin the primary dataset.The Woodcock-Johnson task classificationsand their meaneffect sizescan be found in Table3. RESULTS Gender Effects As shownin Table2, significant genderdifferenceswere found in all task classificationsexceptepisodicmemory knowledge, and verbal fluency in the primary sample, with females outperforming males on tasks of speed(r : +.05) and in the miscellaneouscategory(r: +.07). There was a small advantagein females for tests of verbal fluency (r: +.04), but this differencewas not statistically significant becausethe 95% confidence interval included zero. Males outperformedfemaleson spatial tasks (r : -.18), primary memory/workingmemory tasks(r: -.07), 60 METNZAND SALTHOUSE Ibble 3 Age and Gender Relations on the WoodcockJohnson Test Battery Age Effect (r) TaskType Speed PrimaryAVorking memory Episodic memory Reasoning General knowledge Vocabulary Auditory processing Visual processing Quantitative Miscellaneous 2 ) 2 J J J 2 2 l3 Gender r Age r Male Female .08 .00 .04 -.01 -.04 .05 .03 .09 -.t5 .10 -.62 -.51 -.34 -.55 -.50 -.32 -.14 -.64 -.28 -.49 -.49 -.24 -.04 -.43 -.47 -.30 -.25 -.J I -.) t -.49 -.28 -.08 -.45 -.49 -.30 -.26 -.JU -.5I -.29 -.30 Gender Difference in Aee r .18 -.0'7 -.09 -.01 -.09 -.10 -.09 -.06 .01 -.06 Note-Task type is the task classification formed from variables believed to measurea comrnon cognitive component;j, number ofvariables contributing to efiect size; gender r, point-biserial correlation with gender (male : 0, female : I ); age r, correlation with chronological age; age r for maleVfemales,seeTable I for number ofmale and female participants; gender difference in age r, age x gender interaction term expressedas r"r" (male) - r"r" (female). and testsof reasoning(r: -.08). In general,with the exception of the measuresof spatial abilities, the gendereffects were quite small. into groups by the type of material used: verbal, spatial, numerical, or symbolic (e.g.,the unfamiliar symbols used in associativelearning tasks). Finally, spatial tasks were divided into computerizedand noncomputerizedtasks.In Age Effects order to compute between-grouphomogeneity statistics, Becauseall tasks were scored such that higher scores p", independentmoderator classesmust be formed to indicate higher levels ofperformance, negativeage corre- avoid comparingclassescontainingthe sameparticipants. lations reflect lower scoresassociatedwith increasedage For example,ifa study containsboth paper-and-pencil on a task. As shown in Table 2, in the primary data set,there and reactiontime measruesof speed,then either the paperwere significant negativeagecorrelationson tasksofspeed and-pencil measureor the reaction time measuremay be (r: -.50), spatialabilities(r: -.36), primary memory/ included in the moderator analyses,but not both. The asworking memory(r: -.39), episodicmemory(r: -.35), signment of each task classification to a moderator class reasoning(r : *.38), and on the miscellaneoustasks(r: was random whenevermore than one classof task existed -.39), and there were significantly positive effects of age within a study. on the measuresof knowledge(r : +.23). There was no Table 4 presentsthe gender,age, and difference score significant effect ofage on verbal fluency. effect sizesand the Qr or Qw statisticsfor eachtask classification or moderatorclass for episodic memory, priAge x Gender Interactions mary memory/working memory reasoning,spatial abilities, As noted above,the differencescoresthat serveas efTect and speed(no moderatorsofknowledge, verbal fluency, size indicatorsof gender X age interactionswere com- or miscellaneoustasks were identified and tested).For puted by subtracting female age correlations from male none of these potential moderators was the desired outage correlations; thus, negative difference score effect come of between-groupheterogeneityand within-group sizesindicate larger age-relateddecline in males,and pos- homogeneity obtained;thus, there is little convincing evitive difference score effect sizes indicate larger age- idencethat the effect sizesvaried systematicallyas a funcrelateddecline in females.Table 2 revealssignificant gen- tion of thesefactors.At the presenttime, therefore,we are der differences in the magnitude of age effects on mea- unableto accountfor the significant variability within the suresofspeed (r: +.05) and reasoning(r: +.07), in both various task classifications.Nevertheless,it should be casesin the direction of somewhatsmaller age-relatedde- noted that the confidence intervals for most of the effect cline in malesthan in females. size estimateswere fairly narrow, and, thus, the withincategory variability does not preclude conclusionsabout Moderator Variable Analyses overall effect sizesin the various classifications. Becausealmost all of the Q.. statisticswere significant One point of interest revealedin the moderator analy(seeTable 2), indicating heterogeneityof variancewithin sesis that the gender effects on some of the task classifitask classifications,severalanalyseswere performed in an cations seemto be a result ofdifferential genderrelations attempt to identiff moderatorsof the effects within each acrossmoderator classes.For instance,closer inspection classification. For instance,speedtaskswere divided into of the nonsignificant gender effect on episodic memory two groups: paper-and-penciltasks and reaction time tasks revealsthat there were significant gender effects in (computerized) tasks. Episodic memory, primary mem- the direction of higher performance in females on verbal ory/working memory, and reasoning tasks were divided episodic tasks,but nonsignificant gendereffects on sym- IS AGE KINDER? 6l Thble 4 Gender, Age, and Interactlon Eifect Sizesand Homogeneity Statistics According to Trsk Clesslflcation end Moderetor Classes Gender TaskClassification Speed ModeratorClass Reaction time/Computerized Paper-and-pencil Spatial Reaction time/Computerized Paper-and-pencil PrimaryAil'orkingmemory Numerical Spatial Verbal Episodicmemory Symbolic Verbal Reasoning Numerical Spatial Verbal r+ 24 8 l6 tl J 8 t4 2 8 12 7 5 l2 2 ) ) .04* .03 .06r -.18r -.17* -.lgr -.07* -.13r -. l6r -.03 .03 .00 .09* -.05r .00 -.06 -.04 Age Qror Qw 29.28 19.76t 18.03 11.76 t1< 9.2s 4.46 3.79 0.37 4.51 20.42* t2.04 2.10* 10.73 2.21 6.26 2.86 -.50r -.49* -.51* -.36* - . 3 5r -.3' 7; -.39* -.35* -.4Jt -.37* -.35* -.31r -.40+ -.39t -.36i -.37' -.42* O- or O-, 80.68i 13.89 60.81| 24.83+ 7.58* 20.02t 33.61* 3.94 0.05 26.86* 26.r1, 3.90 l5.41| 74.44* 2-86 33.48r 44.66' Gender Diffr+ .05r -.01 .08r .01 .15t .00 .00 .03 -.04 .00 .02 .04 -.01 .071 . lg * .u) .08r Q, or O* 73.61r t 6.28r 43.01r 50.45r 5.98 44.84* 40.43r 25.57* 3.5r 36.98* 26.27t 23.24i 6.50 76.5f 23.80* 47.99* 6.44 Note-t, number of studies included in analysis; r+, averageweighted correlation; Qr or Qw,total or within-class homogeneity.e1 is reported for the task-classifications(i.e., speed, spatial, primary memory/working memory episodic memory and reasoning), and g; is reportLd foithe moderator classes(i.e., reaction time/computerized, paper-and-pencil,numerical, spatial, verbal, and symbolic). tp . .OSinonho-ogeneity). bolic episodic memory tasks. Similarly, the male advantage on primary memory tasks seemsto be a result of higher levels of performanceon numerical and spatial tasks,but not on verbal primary memory/working memory tasks.Also, the female advantageon speedtasks appears to be a result of superior female performance on paperand-pencil tasks,but not on reaction time speedtasks. With regard to the gender differences in age effects, differencesin the direction of lesserage-relateddecline in males were more pronouncedon verbal and numerical (relative to spatial) reasoningtasks,on computerized(relative to paper-and-pencil)spatialtasks,and on paper-andpencil (relative to reaction time) speed tasks. However, theseresultsshouldbe interpretedwith cautionbecauseof the random assignmentto moderatorclassesand the small number of studieswithin the moderator classes. In order to examinethis possibility,I'tests of equalvariancewere performed to comparethe variancesof age and ofthe dependentvariablesacrossgender.Becausethe raw dependentvariableswere in different units, they were converted to a common metric within each studv bv transforming them into standardscoresbasedon the distribution of both males and females.The standardscoreswere then averagedto form one index ofthe dependentvariable for each task classification within a given study. Sigaificant F tests would indicate that the variance of femalesand males differed, and, if this were the case,the gender differences in age correlations might be partially attributable to a smaller range of variation in one gender than in the other. Howeveq the results of these analyses, summarized in Appendix C, indicate that there were no significant genderdifferencesin the agevariances,and there were significant gender differences in only 3 of 89 comVariance Analyses parisons(one each in the speed,episodic memory and The correlation coefficients (r) usedhereas an index of miscellaneouscategories)on the dependentvariables.The effect size are a function of the slope of the linear rela- small number of significant F testsmakesit unlikely that tionship between age and performance on the dependent the pattern of results reported in this study were attributvariable, the variance ofage, and the variance ofthe de- able to genderdifferencesin the amount of variation in eipendent variable. It is therefore possible that gender dif- ther age or the dependentvariable. Theseresults are also ferencesin the varianceeither on the dependentvariables of substantiveinterestbecausethey imply that, at least in or on age could distort the comparisonsofthe age corre- these samples,adult males and females do not differ siglations betweenmales and females. In other words, gen- nificantly with respectto interindividual variability on der differences in the age correlation on a given depen- measuresof cognitiveabilities. dent variable may be partially attributable to greater age variation or to greater variation in the dependentvariable Summary in one gender relative to the other. In fact, male children The patternof gender--cognitionrelationsin the primary havebeen found to be more variable than female children datasetwas mixed, and, with the exceptionof the spatial in numericaland spatialabilities(seeMaccoby& Jacklin, measure,the effect sizes were quite small. There were 1974.for a review). largeageeffectson most of the variables,with negativeef- 62 MEINZ AND SALTHOUSE fects of age on measuresof speed, spatial abilities, primary memory/working memory and episodic memory but positive effects ofage on knowledge, and no age effectson verbal fluency.Small interactiveeffectsofage and genderwere found, with a significant advantagefor males in speedand reasoning.The results ofvariance analyses suggestedthat it is unlikely that the results were influencedby gender differencesin the variance ofage or the variance of the dependentvariables. The Woodcock-Johnsondata were analvzed for comparisonwith the primary dataset.No confiience intervals could be establishedin this data set becauseeachparticipant performed every task in the battery and, thus, only the magnitude of the effects can be examined.Inspection ofTable 3 reveals that gender effects in these data were small with the exception of a moderate gender effect in quantitative abilities, in the direction ofhigher levels of performancein males.The agetrendswere similar to those in the primary data set in that there were moderatelynegative effects of age on all measuresexcept vocabulary. Surprisingly, the effects of age on knowledge in this data setwere negative.As in the primary dataset,the direction of the interaction effects were mixed. Greaterage-related decline was evident among females on the measureof speedand among males on severalof the other measures. DISCUSSION Although considerableeffort has been devotedto documenting gender differences in the relations of age to brain morphology and functioning, few studieshave confirmed thesefindings with behavioral data.A meta-analysis was therefore performed on 25 data sets encompassinga wide variety of cognitive taskswith the goal of examining age X gender interactions on cognitive measures.The main effectsof age and genderwere also examinedfor the purpose of comparison with the literature on gendercognition and age-+ognition relations. Becausemost of the analysesrevealedevidenceofheterogeneity, it is possible that sometrue effects were concealed.Nevertheless, the confidence intervals for estimated effect sizes were relatively narrow and, thus, the results can be considered reasonablyprecise. The gender--cognitionrelations found in the primary datasetwere, for the most part, similar to thosefrequently reportedin the literature. It shouldbe noted that, while the present analysis revealedmostly male advantages,some measuresat which'femaleshave been reportedto excel (notably reading comprehensionand writing) were not included(Halpern, 1992). Males outperformed females in spatial abilities, which is consistentwith the results of a meta-analyticreview by Linn and Petersen(1986) and otherreviews(e.g.,Schaie, 1994). We found no significant gender differences on measuresof verbal fluency or knowledge. Prior studies have been mixed on this issue because,while there have beensomereports of a female advantagein generalverbal abilities(Hyde & Linn, 1986;Schaie,1994),otheranaly- seshaverevealeda female advantageon testsofanagram solution, general verbal abilities, and analogies, but no difference in vocabulary (Hyde & Linn, 1986) or general knowledge (Herlitz et al., 1997).In this study, females were faster on tests of speed, but there was a male advantage in reasoning.The latter result is inconsistentwith the work of Schaie (1994), in which a female advantagein testsof inductive reasoningwas noted. One inconsistencyconcernsthe gendereffectsreported on episodicandprimary memory tasks.Herlitz et al. (1997) investigatedgenderdifferenceson episodic,semantic,and primary memory tasks.While they also reported no gender differencesin semanticmemory (which included tasks similar to those in the knowledge classification), they reported sizablegender differences on severalepisodic memory tasks,in the direction ofhigher levels ofperforrnance in females,and no genderdifferenceson testsof primary memory. On closer inspection,however,the apparentdiscrepanciesbetweenthe Herlitz et al. study and the present analysesare most likely attributable to the types of tasks used, becausethc moderatoranalysesrevealedthat, when consideringonly verbal tasksas in the Herlitz et al. study, there was a female advantageon episodic memory tasks, and there were no gender differences in primary memorylworking memory tasks.Theseresults suggestthat the type of stimulus material (e.g., verbal, spatial) should always be consideredwhen investigatinggenderdifferences in broad task classifications. The gender relations in the Woodcock-Johnson data, for the majority of measures,were consistentwith thosein the primary data set. One exception is in the case of vocabulary where females performed at higher levels than males did. The largestrelation with genderin this data set was for the quantitative measures.Superior quantitative performancein maleshasbeenfound by someresearchers (Hyde, l98l; Schaie,1994),but not others(Hyde, Fennema,& Lamon, 1990).It is possiblethat theseinconsistenciesare simply the result of the magnitudeof the gender effects;the effectsare fairly small and greaterthanr: . I on only two measures(spatial and quantitative). The age-relatedeffects in this study were similar to those reported in other cross-sectionalstudiesin that substantial negative relations of age on measuresof speed, primary memory/workingmemory episodicmemory spatial abilities, and reasoningwere found (seeBlanchardFields & Hess, 1996,and Craik & Salthouse,1992,for reviews). It remainsto be seenwhether comparablepatterns would be evident in longitudinal designs,and resultsfrom more extensivesequentialdesigas are neededbefore the source(i.e., endogenousor exogenous)of theseeffects can be identified. Discrepanciesexisted between the Salthouseand Woodcock-Johnsondata sets in terms of the relation of age to measuresof knowledge. The data from Salthouse and collaboratorssuggestmoderatepositive ageeffectson measuresof knowledge (generalknowledge and vocabulary). Although there was a small positive age relation on the two vocabulary measuresin the Woodcock-Johnson IS AGE KINDER? data, there was a negative relation between age and other measuresofknowledge (generalknowledge:socialstudies, science,and humanities). It is not clear whether the different patternsof agerelations on measuresof knowledge are due to differences in the nature of the samples (i.e., conveniencesamplesvs. representativesamples)or to other factors.One factor that could be involved is amount ofeducation. While education level is very similar acrossage in the studiesby Salthouseand his collaborators,the education level in the Woodcock-Johnsondatadecreaseswith age,reflecting population trends. However,this factor is not responsible for all of the differences in age-knowledge relations between the data sets,becausea negative ageknowledge relation remains after statistical control of educationin the Woodcock-Johnsondata set. The findings of primary interest in this study are those concerning the interactions ofage and gender.Although the majority of results from studiesbasedon neuroanatomical data suggest greater age-related atrophy and functional loss in males than in females, the only significant interactions found in the analysisof the primary data set were in the direction of greaterage-relateddecline among femalesthan among males.Thesedataare consistentwith Schaie's(1994) idea that, if anything, women decline earlier on some fluid abilities, such as perceptualspeedand reasoning.Schaiealso suggestedthat women show decline earlier on verbal fluency,and men on crystallized abilities, but thesespeculationswere not supportedin the presentanalyses.Moderator variable analysessuggested that genderdifferencesin age-rognition relations may be related to the type of stimulus material (e.g., verbal, spatial) or method of task administration(e.g., computerized/ reactiontime, paper-and-pencil), but more investigation is neededbefore strong conclusionscan be drawn. The pattern of resultsin the Woodcock-Johnsondatawas mixed, but, again, almost all of the effects were very small. In conclusion,the resultsofthese analysesrevealthat there are large (i.e., between l2oh and 25o/oof the total variance)effectsrelatedto age,small (i.e.,at most 3%oof the variance)effects associatedwith gender,and small to nonexistent(i.e., less than l%o)effects associatedwith interactions of age and gender on measuresof cognitive performance. As discussedin the introduction, evidencefor differential patterns of aging between men and women has been reported with someneuroanatomicalmeasures.However, theseresults have been somewhatinconsistentwith respectto which genderexhibited greaterage-relateddecline, and, apparently,no meta-analyticintegrationsof the neuroanatomicalfindings havebeenpublished.The most convincingresolutionofthe discrepancies betweenstudies with neuroanatomicalvariables and with cognitive variableswill likely require studieswith moderatelylarge samplesof femalesand males from a wide agerangewho eachcontribute both neuroanatomicaland cosnitive data. -evidence Unless,and until, such studiesyield strong of significant age X gender interactions,any speculation about the basis for differential aging among females 63 and males seems premature. REFERENCES BrrNcnrno-Frnros, F., & Hnss, T. M. (Eos.) (1996). Perspectives on cognitive change in adulthood and aging. New York: McGrawHill. CowsLL, P.E., Tunrrsxl B. 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APPENDIXA Task Descriptions Task Speed Letter comparison Patterncomparison Number comparison Finding,4s Digit symbol substitution Number matching Patternmatching Letter completion Number completion Number transformation Letter transformation Digit copy Number copy Letter copy Symbol copy Description Write the letter S if pairs of letters are physically identical; otherwise, write the letter D. Write the letter S if pairs of line patternsare physically identical; otherwise, write the letter D. Indicate with a wrinen response*trich pairs of numbers are physically identical. Mark with a written responsethe items that contain the letter A. Write the symbol associatedwith a digit according to a code table. Mark with a written responsewhich of severalalternative setsof numbers matchesthe target numbers. Mark with a wdtten responsewhich of severalalternative sets of patternsmatchesthe target pattern. Write the letter that is missing from one of two pairs of letters. Write the digit that is missing from one of two pairs of numbers. Write the digit that would result by adding either I or 2 to the displayeddigit. Write the letter that would result by going one or two letters forward in the alphabetic sequence. Copy the displayed digit in the spaceimmediately below or adjacentto it. Copy the displayednumber in the spaceimmediately below or adjacentto it. Copy the displayed letter in the spaceimmediately below or adjacentto it. Copy the displayed symbol in the spaceimmediately below or adjacentto it. IS AGE KINDER? Word copy Boxes Line marking Counting backwards Naming time Trail making Digit digit Digit symbol Memory search Duration threshold Spatial Cube assembly Paperfolding Spatial rotation Block design Object assembly Surfacedevelopment Perceptualclosure Primary/Working Memory Sentencespan Computation span Word span Digit span Letter memory Keeping track (numeric) Keeping hack (spatial) Matrix memory (verbal) Matrix memory (spatial) Element memory (verbal) Element memory (spatial) N-back Episodic Memory Associative memory Copy the displayed word in the space immediately below or adjacentto it. Draw a line to make a three-sided figure into a square or box. Draw vertical lines through short horizontal lines, or draw horizontal lines through short vertical lines. Count backwardsby a designatedquantity (e.g., ones, threes,etc.). Read visually presentedwords. Connect haphazardlypositioned circles according to numerical or alternating numerical and alphabetical sequences. Pressone key iftwo digits are identical; otherwise, pressa different key (speed). Pressone key ifa digit and symbol match according to a code table; otherwise, pressa different key (speed). Classifu a probe item with respectto whether it was (by pressing one key) or was not (by pressing another key) in the previously presented memory set (speed)(Sternbergmemory searchtask). Perform three simple arithmetic operations (psychophysically determined minimum time needed). Decide whether arrows on two of six connectedboxes would point at one another ifthe boxes were assembledinto a cube (speed and accuracy). Determine whether a particular pattern of holes would result if a piece ofpaper were folded in the designatedfashion and a hole punched in the specified location (speedand accuracy). Identifu by a written responsewhich ofseveral alternative patternsis physically identical to the target pattern but merely rotated in the sameplane (speedand accuracy). Assemble a set of blocks to produce a pattern that matchesthe target pattern (speed). Rearrangea set ofpuzzle pieces to form a complete object (speed). Determine the correspondencebetweendesignatedpositions across two- and three-dimensionaldrawings of the sameobject (speedand accuracy). Identi$ objects from degradedpictures (speedand accuracy). Rememberthe last word in each sentencewhile also answering questions about the sentences(accuracy). Rememberthe last digit in eacharithmetic problem while also solving the arithmetic problem (accuracy). Rememberas many words in sequenceas possible (accuracy). Remember as many digits in sequenceas possible (accuracy). Remembera sequenceofthree, five, or sevenletters (accuracy). Remember the latest value of a set of digits that are repeatedly updated by meansof arithmetic operations(accuracy). Rememberthe latest position of a set of asterisksthat are repeatedly displacedby meansof arrows of varying length and orientation (accuracy). Rememberthe identities of 7 target letters from a set of 25 letters (accuracy). Rememberthe positionsof 7 targetlocationsfrom a set of 25 positions (accuracy). Decide whether a single letter was presentedin an earlier memory set (accuracy). Decide whether a single line segmentwas presentedin an earlier line pattern (accuracy). Report the digit N items back in a sequence(where N : 0, 1, or 2) (accuracy). Recognizewhether elementsof a particular pair (i.e., digits, letters, or symbols) were previously paired together when either member of the pair was last presented(accuracy). 65 66 MEINZ AND SAIJTHOUSE APPEIIDD( A (Continued) Task Associative learning Name-number association Paired associate Free recall RAWT (Rey auditory verbal learning test) Activitymemory Frequencyjudgment Maze learning Temporal memory Reasoning Raven'sprogressivematrices Number seriescompletion Integrative reasoning Geometric analogies PMA reasoning Shipley abstraction Cattell's matrices Letter sets Knowledge Vocabulary Shipley vocabulary General information Verbal Fluency Letter fluency Sequentialassociates Make words Miscellaneous Arithmetic computation Sentencecomprehension Stroop interference(color) Stroop interference(position) Stroop interference (number) Anagram Description Select the secondmember of a pair of elements(i.e., digits, letters, or symbols) when presented with the first member of the pair (accuracy). Remember the pairings between numbers and names (accuracy). Recall the second member of a pair of words when presented with the first member of the pair (accuracy). See or hear a list of l2-20 unrelated words and immediately attempt to recall them in any order (accuracy). Recall a set of l5 unrelatedwords with repeatedstudy-recall presentations (accuracy). Recognizethe order in which a set of activities was performed in a session(accuracy). Decide the frequency with which words were presented (accuracy). Make choice decisions acrosssuccessivetrials in a spatial maze (accuracy). Reproduce the temporal order in which I 6 words appeared (accuracy). Selectthe best completion of the missing cell from a matrix containing geometric patterns(accuracy). Identiff the best continuation ofa seriesofnumbers (accuracy). Decide the truth of a statementpertaining to two elementsgiven a set of premisesdescribing relations among premises(accuracy). Decide which ofseveral alternativesrepresentsthe best D term for A:B is to C:D1,D2,D3, with stimuli consisting of geometric patterns (accuracy). Complete a seriesof numerical items (accuracy). Complete a seriesof numerical and verbal items (accuracy). Select the best item for completion of the missing cell from a matrix containing geometric patterns(accuracy). Decide which set ofletters does not fit with the others (accuracy). Selectwhich alternative is the best synonym or anton)rmofthe target word (aecuracy). Selectwhich alternative is the best synonym or antonym ofthe target word (accuracy). Selectwhich alternative is the best answerto questionson a variety of topics ranging from American History to Geography,Mythology, Music, and World Literature (accuracy). Generatewords that begin with a specified letter (number generated within a specifedamount of time). Generatewords that are associatesof the preceding item (number generatedwithin a specified amount of time). Create as many words as possible from a set of letters (number createdwithin a specified amount of time). Carry out elementary arithmetic operations(speedand accuracy). Answer simple verbal comprehensionquestions(speedand accuracy). Name ink colors when the targetsare words of diferent colors (speed). Name target positions when the targets are words indicating different positions (speed). Name the number of elementswhen the elementsare digits representingdifferent numbers (speed). Rearrangea set of letters to make a word (number completed). IS AGE KINDER? APPENDD(B Age and Gender Reladons from Individual Studies ln the Primary Analysis Study i Gender r I 2 3 2 -.10 .07 .05 .05 .06 .09 .05 .03 .00 -.01 .15 .03 -.05 .00 .t2 .03 J 4 ) 6 7 8 9 l0 ll t2 I J t4 l5 l6 l8 l9 20 2l 22 23 24 25 z 4 J 3 J J 0 6 7 6 8 7 7 0 .t I J 6 7 4 2 z 8 z .01 -.01 .ll .18 .10 -.11 .15 3 6 7 9 1 2 13 15 2 0 2 2 24 2 5 l 2 2 l 2 I 1 3 2 I 2 -.20 -.t4 -.08 -.22 -.24 -.13 -.18 -.14 -.10 5 6 7 8 t4 t5 l6 17 l8 l9 2l 22 2 2 -.09 -.01 -.0'7 .04 -.06 -.09 -.07 ZJ 24 z z 6 z I 4 4 I J z z z - -JZ -.18 -.ll -.01 -.05 -.06 -.08 -.12 -.ll Age Correlation (r) Gender Difference Female in Age r Age r Male Speed Tasks -.48 -.51 -.62 -.47 -.56 -.64 -.55 -.60 -.45 -.52 -.39 -.49 -.35 -.50 -.52 -.58 -.60 -.59 -.56 *.46 -.52 -.53 -.54 -.24 -.48 -.52 -.01 .00 -.t7 .02 .05 -.53 -.50 -.58 -.54 -.56 -.52 -.40 -.60 -.60 -.50 -.18 -.47 -.50 -.56 -.48 -.58 -.72 -.55 -.61 -.54 -.49 -.38 -.49 -.40 -.48 -.55 -.58 -.64 -.68 -.58 -.50 -.46 -.48 -.49 -.34 SpatialTasks -.38 - -35 -.17 -.18 -.34 -.4t -.39 -.32 -.38 -.35 -.28 -.19 -.43 -.53 -.46 -.47 -.25 -.24 -.59 -.48 -.34 -.25 - .43 -.13 -.26 -.43 -.39 -.33 - .4r -.46 -.23 -.39 -.41 .09 -.05 -.17 .13 .04 .15 -.15 -.01 -.02 -.26 .t7 - .45 -.44 -.42 - .34 -.47 -.25 -.62 -.39 -.41 -.48 -.2s -.41 -.38 -. 15 -.09 -.05 .01 -.01 .09 -.tJ -.46 -.54 -.59 -.56 -.54 -.35 -.56 -.41 -.50 Primary/WorkingMemory -.48 -.53 -.46 -.48 -.42 -.41 -.34 -.35 -.43 -.39 -.32 -.43 -.54 -.47 -.44 -.51 -.JJ -.23 -.36 -.28 -.26 -.28 -.42 -.43 -.41 - .44 -.16 - .17 .23 -.01 .10 .23 -.09 -.05 -.01 .14 -.06 .07 .00 .16 .20 .09 .13 -.19 -.17 -.01 .17 -.Ll .21 -.16 .20 -zJ -.05 -.02 -.07 -.01 67 68 MEINZ AND SAIJIHOUSE Study 9 l0 ll t2 l3 t4 15 l6 20 2l 22 23 2 2 2 2 I I 2 2 2 I r 2 2 3 5 6 2 l 2 2 t z 9 3 2 I I 2 2 t 2 13 20 2 3 2 5 J J APPEITIDD(B (Condnued) Age Correlation(r) GenderDifference Genderr Male Female in Ase r EpisodicMemory -.40 -.38 -.43 .08 .06 -.01 -.35 -.39 -.32 -.09 -.25 -.15 -.35 .11 .21 -.27 . 2 4 -.31 .08 .07 -.27 -.22 -.31 .04 .10 -.09 -.41 -.31 -.49 .21 -.04 -.33 -.40 -.30 -.ll -.52 -.50 -.57 .t7 .09 -.50 -.55 -.48 -.10 .t2 -.19 -.33 -.38 -.35 -.03 -.23 -.28 -.19 -.09 .04 -.29 -.32 -.05 .05 -.16 .04 .00 -.11 -.03 -.13 -.02 -.16 -.05 .00 -.33 -.03 2 2 2 -.04 -.08 -.0'l -.03 .02 .01 -.06 I 2 l6 2 -.01 -.02 .17 I l6 t7 l8 24 I I 2 2 I 2 J l6 l9 20 2l z I Reasoning -.42 -.33 -.50 -.58 -.67 -.65 -.35 -.35 -.42 -.38 -.46 -.49 -.35 -.22 -.Jt -.40 -.09 .t4 -.45 -.46 -.36 -.37 -.26 -.18 Knowledge .27 .31 .t2 .05 .13 .13 .t7 .25 .52 .59 .25 .19 .23 .19 VerbalFluency -.ll -.06 -.18 -.33 .24 .34 -.44 -.44 -.68 -.35 -.47 -.41 -.44 -.31 -.25 -.44 -.36 -.33 .13 -.19 .05 .00 . lI -.10 .25 -.10 .38 -.03 -.01 .16 .2'l .16 .t2 .13 .39 .28 .26 .04 -.t2 .01 .12 .26 -.10 -.07 -. 13 -.10 .19 .08 -.24 .16 .00 -.58 -.51 -.51 -.32 .10 -.08 -.09 .16 .03 Miscellaneous J .01 .03 .05 .10 .16 .04 -.60 -.55 -.46 -.3I .10 -.63 -.58 -.38 *.30 Note-For study numbers, see Table 1;7, number of variables contributing to effect size; gender r, point-biserial correlation with gender (male = 0, female : l); age r, correlation with chronological age; age r for males/females,seeTable I for number of male and female participants; gender difference in age r, age X gender interaction term expressedas r"r"(male) - r"r"(female). IS AGE KINDER? APPEI\DD(C Standard Deviations for Age and Thsk Classilication According to Gender Age Dependent Variable SD SD Study I 2 J 4 5 6 7 8 9 l0 ll t2 l3 t4 l5 l6 l8 l9 20 2l 22 23 24 25 5 6 7 9 t2 l3 l5 20 22 24 25 5 6 7 8 t4 15 l6 t7 18 l9 2l 22 1A df Male Speed t 7. 3 t 14.17 t6.t2 14.65 16.57 r7.2t t 7. t 4 t6.4t 16.33 15.89 15.82 t6.49 16.48 18.99 t6.79 19.89 t6.22 t9.46 I8.89 t6.17 t6.07 t 7. 2 1 16.39 16.44 1.32 l.l4 t.l I t.4l 1.28 l.l0 t.l2 t.26 1.09 1.03 I .18 r.r4 l.14 I .15 l.l6 1.0' 1 t.07 l.l I r.r4 1.33 l .l0 |.02 1.33 L06 0.76 0.85 0.91 0.82 0.89 0.89 0.89 0.78 0.59 0.84 0.54 0.81 0.66 0.95 0.80 0.60 0.84 0.77 0.66 0.81 1.08 0.80 0.73 0.85 0.87 0.94 0.90 0.73 0.91 0.93 0.90 0.98 0.63 0.75 0.55 0.80 0.7r 0.85 0.74 0.55 0.94 0.82 0.75 0.82 0.68 0.99 0.74 0.83 1.33 t.22 1.02 t.26 1.03 1.09 1.03 1.57 l.16 1.28 1.03 1.02 t.t1 r.27 l.l8 t.t7 r.25 l.l4 1.32 t.02 2.52* 1.55 r.02 1.05 Spatial t6.t2 1 7. 2 t 17.t4 16.33 t6.49 16.48 16.79 18.89 16.07 16.39 16.44 I .l I Ll0 t.t2 1.09 1.14 l.l4 1.16 r .1 4 l.l0 1.33 1.06 1.00 0.81 0.74 1.00 0.90 1.00 1.00 0.83 0.78 L05 0.95 0.95 0.74 0.65 1.04 0.73 1.04 0.98 0.87 0.'76 0.88 0.85 l.l l l.l9 r.27 l.08 1.50 1.08 1.04 L l0 r.07 1.41 t.24 PrimaryAV'orking Memory 18.72 16.57 1.28 18.06 17.21 1.10 18.1l t7.r4 r.12 18.44 t6.4r r.26 20.40 18.99 1 l5 ts.62 16.79 1.16 20.60 19.89 1.07 18.47 1s.12 r.49 t6.79 16.22 r.07 20.47 19.46 r. r l 18.67 16.17 1.33 1 6 . 8 s 1 6 . 0 7 1 .l 0 t7.4t r7.2r 1.02 18.89 16.39 1.33 0.94 0.91 0.94 0.92 0.39 0.89 l.16 0.92 0.77 0.97 0.78 0.81 0.82 0.92 0.83 0.90 0.86 0.87 0.35 0.78 0.91 0.73 0.81 1.04 0.79 0.82 0.82 0.85 r.28 1.01 l .l 9 r.t2 |.22 |.28 1.63 1.59 l.l0 1.14 t.02 t.02 r.02 t.t1 (58,142) (90,126) (85,108) (42,84) (85,134) 19.90 13.30 15.33 17.42 t8.72 (r24,r02) 1 8 . 0 6 ( l 0 e , ll 2 ) 1 8 . I1 (s2,46) 18.44 ( 123,180) r7.09 (85,l 53) 16.t4 (5e,64) r7.20 (e4,l 50) r7.63 ( 1 0 1 , 1 5 5 ) 17.64 (79,92) 20.40 (5e,56) 15.62 (60,1l6) 20.60 ( e 3 ,3 18 ) r7.69 (7e,50) 20.47 ( 163,94) r 7 . 6 7 (82,1 3) 18.67 (s7,70) 16.85 (107,r24) t't.41 (l0l,l0e) 18.89 ( 185,1e6) 16.93 (85,108) (124,r02) ( 1 0 9 ,l12 ) ( 123,180) (e4,l 50) (101,15s) 15.33 18.06 l 8 . lI 17.09 t7.63 t7.64 (se,s6) 15.62 ( 163,e4) 17.67 (s7,70) 1 6 . 8 5 ( 1 0 1 , 1 0 e )1 8 . 8 9 (l 85,196) 1 6 . 9 3 (85,134) (124,t02) ( 1 0 9 ,1r 2 ) (s2,46) (79,92) (59,s6) (60,116) (l l0,l 15) (93,138) (79,50) (82,113) ( 5 7, 7 0 ) (r07,124) (101,109) 69 MEINZ AND SALTHOUSE APPEIIDD( C (Conttnued) DependentVariable SD study df EpisodicMernory 17.09 16.33 I .09 16.t4 15.89 1.03 17.20 15.82 l.l8 1 7. 6 3 t6.49 t.t4 17.64 16.48 l.l4 20.40 18.99 l.l5 15.62 16.79 1.16 20.60 19.89 t.07 t 7. 6 7 18.89 I .14 18.67 t6.17 1.33 16.85 16.07 l.l0 t7.4r t7.2t l.o2 0.89 0.83 0.86 0.75 1.03 0.94 0.93 0.87 0.88 1 .l 4 0.69 0.68 0.95 0.83 0.89 0.75 0.98 L08 0.83 0.88 0.89 0.82 0.70 0.68 t.t4 l.0l t.07 r.02 t.r2 r.32 r.26 1.04 t.02 1.95* r.02 1.00 ( 1 0 9 ,l12 ) ( 123,180) (e4,l 50) ( l 0 l ,I 5 5 ) ( 163,e4) (107,r24) ( 185,196) 19.90 13.30 15.33 r 8.73 18.06 l 8 . l1 r 7. 0 9 t 7. 6 3 t 7. 6 4 t 7. 6 7 t 7. 4 1 16.93 Reasoning r 7. 3 t 1. 3 2 r4.r7 1.14 r6.t2 l.1l 16.57 I .28 t 7. 2 1 l .10 r 7. r 4 t.t2 16.33 1.09 t6.49 r.t4 16.48 | .14 I8.89 t.t4 t 7. 2 1 1.02 \6.44 L06 0.90 0.95 L00 0.84 0.81 0.74 t.o7 0.95 l.0l 0.98 0.90 0.91 0.92 0.80 0.99 0.91 0.77 0.66 1.12 0.78 1.00 1.02 0.84 0.92 1.05 r.42 l.0l 1.18 l. I I t.27 I .08 1.48 r.02 L09 l.l3 l.0l (58,142) (90,t26) (85,108) (60,I l 6) (7e,50) (163,e4) (82,I l 3) 19.90 13.30 15.33 20.60 20.47 r 7. 6 7 18.67 Knowledge 17.3t t.32 r4.r7 1.14 16.t2 1.1I 19.89 1.07 19.46 l.1l 18.89 | .14 r6.l't 1.33 0.94 0.82 0.83 0.98 1.03 0.99 0.99 0.96 0.96 0.93 I .01 0.98 I .01 0.99 1.04 1.35 1.26 I .07 Llo I .05 1.02 VerbalFluency (58,142) 19.90 t'1.3r r.32 (e0,126) 1 3 . 3 0 r 4 . r 7 l.l4 (60,I I 6) 20.60 19.89 t.O1 1.02 0.82 0.80 0.87 0.94 l .08 1.35 t.32 r.82 Miscellaneous 19.90 17.3r r.32 13.30 r4.r7 r.t4 20.60 19.89 1.07 18.47 ts.t2 1.49 16.79 16.22 r.07 18.89 16.39 1.33 1.04 0.91 t.t4 0.95 0.85 0.61 0.99 1.05 0.94 0.88 0.95 0.84 r.r2 I .33 r.46 L16 1.26 l.9l,r. 9 l0 ll l2 l3 t4 l5 l6 20 2l 22 23 (123,l 80) (85,r 53) (5e,64) (e4,l 50) (r01,155) (79,92) (5e,s6) (60,1l 6) ( l 63,e4) (82,1 l3) (57,70) (107,r24) I 2 (58,142) (90,126) (85,108) (85,l 34) J 5 6 7 9 l2 l3 20 z3 25 I 2 -t l6 l9 20 2l I 2 l6 I 2 16 t7 l8 AA Male (r24,r02) (58,142) (90,1 26) (60,1l 6) ( l 1 0 , l1s ) (93,138) (101,10e) Note-The F testswere computed by dividing the larger variance value (females or males) by the smaller variance vahte. df = (number of males - l, number of fem a l e s- l ) . * p . . 0 5 . (ManuscriptreceivedJanuary3l, 199'l; revisionaccepted for publicationSeptember 9, I 997.)