Randy Ludwig The Biology of Love, Sex & Attraction
TNDY 402 FEB 14— 2011
OVERVIEW:
1.
2.
3.
4.
Types of LOVE
Biochemistry of LOVE
Applications
Conclusion
A few Stats:
Age of first marriage:
Women: 24.8 years
Men: 27.3 years
The probability of first marriage by age 30:
74% for women
61% for men.
The probability of first marriage by age 40:
86% for women
81% for men.
(Goodwin, McGill, & Chandra, 2009)
A few Stats:
17% of women & 25% of men have not married by age 35.
12% of women have not married by age 40,
17% of men have not married by age 40.
The probability that men and women will marry by age 40 is over
80%.
(Goodwin, McGill, & Chandra, 2009)
TYPES:
If it feels different, it is different
1.
2.
3.
4.
Lust (Sex)
Passionate Love (Infatuation/Romantic Love)
Companionate Love (Attachment)
Maternal Love
TYPES:
Lust/Sex:
•
Non-selective sex, goodness of fit not important
Main Drivers:
1.
Testosterone: (C19 H28 O2 )
• Increases sexual arousal in men & women
2. Estradiol: (C18 H24 O2 )
• Associated with higher sexual activity in women
• Higher masturbation rates
• Preference for “manly” faces
3. Dopamine & Norepinephrine
Key Brain Areas Involved:
1.
2.
3.
4.
5.
Medial insula
Anterior cingulate
Hypothalamus
Nucleus accumbens
VTA
TYPES:
Passionate Love:
•
Exhilaration and euphoria
Increases in:
1.
2.
3.
Dopamine: (DA)
Norepinephrine: (NE)
Nerve Growth Factor (NGF)
Decreases in:
1.
2.
3.
4.
Serotonin: (5HT)
Frontal Lobe
Amygdala
Parietal lobe
Excess DA & NE tend to
reduce 5HT Obsession
Key Brain Areas Involved:
1.
2.
3.
4.
5.
6.
Anterior cingulate
Hippocampus
Nucleus accumbens
Hypothalamus
VTA
Caudate nucleus
Pleasure Centers In the Brain:
Orbitofrontal
Cortex (OFC)
Cingulate Gyrus
Thalamus
2. ________
3. ________
Corpus Callosum
1. ________
Nucleus Accumbens
11. ________
Cerebellum
4. ________
Hypothalamus
10. ________
Pituitary Gland
9. ________
Amygdala
Hippocampus
5. ________
8. ________
Medulla
Pons
7. ________
6. ________
TYPES:
Companionate Love:
•
•
Calmer type of love, emotional bond
EX: grandparents married for 30 years
Increases in:
1. Oxytocin: (OXT)
2. Vasopressin: (AVP)
Decreases in:
1. Serotonin: (5HT)
•
•
•
Chemically similar
Produced in hypothalamus
Released from pituitary gland
TYPES:
Maternal Love:
•
Parent & child
Increases in:
1. Oxytocin: (OXT)
2. Vasopressin: (AVP)
Brain implications:
•
Decreases in:
1. Serotonin: (5HT)
•
•
Hypothalamus not
activated
Striatum is activated
Slight reduction in
frontal lobe
APPLICATIONS:
Prairie Voles:
•
•
Socially monogamous (mate with others at times)
High levels of OXT & AVP receptors
• If OXT & AVP blocked: they become promiscuous
Montane Voles:
•
•
•
Promiscuous
No long-term attachment
OXT & AVP injections in
montane voles doesn’t lead to
monogamy—why?
Clark & Hatfield (1989):
• Students were approached by another
student of the opposite sex, who said:
• “I have been noticing you around campus
and I find you very attractive.”
• This was followed by one of three invitations:
– “Would you go out with me tonight?”
– “Would you come over to my apartment?”
– “Would you go to bed with me?”
Percent Saying “Yes”
100
80
60
About half of both
sexes said “yes” to
the date
40
20
0
Go Out
Go to Apt.
Go to Bed
Percent Saying “Yes”
100
80
60
About half of both
sexes said “yes” to
the date
40
20
0
Go Out
Go to Apt.
Go to Bed
Percent Saying “Yes”
100
80
60
About half of both
sexes said “yes” to
the date
40
20
0
Go Out
Go to Apt.
Go to Bed
Not a single
woman said
“yes” to the
sexual
invitation
Percent Saying “Yes”
100
80
60
About half of both
sexes said “yes” to
the date
40
20
0
Go Out
Go to Apt.
Go to Bed
Not a single
woman said
“yes” to the
sexual
invitation
Percent Saying “Yes”
100
Men were even more
likely to say “yes” to the
sexual invitation
If men said “No,”
then they typically
apologized and/or
offered an excuse
such as “I’m
dating someone”
80
60
About half of both
sexes said “yes” to
the date
40
20
0
Go Out
Go to Apt.
Go to Bed
Not a single
woman said
“yes” to the
sexual
invitation
Mate Preferences of Women
•
•
•
•
•
•
•
•
•
•
Economic Resources
Good Financial Prospects
High Social Status
Older Men
Ambition and Industriousness
Dependability and Stability
Athletic Prowess
Good Health and Physical Appearance
Love and Commitment
Willingness to Invest in Children
Mate Preferences of Males
• Desire women who are:
– Intelligent, kind, humorous, understanding, &
healthy
– Similar in terms of values, personality, and
religious beliefs
In Addition...
• Youth
• A cue for fertility
Mate Preferences of Males
• Youth
• Physical Beauty
• full lips, clear skin, smooth skin, clear eyes,
lustrous hair, good muscle tone, &
attractive body fat distribution
• Behavior: youthful gait, animated facial
expression, & high energy level
– “Average” & symmetrical faces are more
attractive
Mate Preferences of Males
• Youth
• Physical Beauty
• Body Fat and the Critical Waist-to-Hip
Ratio (WHR)
– Universal preference across cultures...
– .70 is optimal
References:
Clark, R.D., & Hatfield, E. (1989). Gender differences in receptivity oto
sexual offers. Journal of Applied Social Psychology, 20, 771-782.
Fisher, J, Aron, A, & Brown, L.L. (2005). Romantic Love: an fmri study
of a neural mechanism for mate choice. The Journal of
Comparative Neurology. 493:58, 58-62.
Fisher, H.E., Aron, A., Mashek, D., Haifang, L., & Brown, L.L. (2002).
Defining the brain systems of lust, romantic attraction, and
attachment. Archives of Sexual Behavior. 31:5, 413-419.
Johnson, S. (2009). Addicted to love. The Brain. Winter, 50-55.
Savulescu, J., & Sandberg, A. (2008). Neuroenhancement of love and
marriage: The chemicals between us. Nueroethics. !:31, 31-44
Zeki, S. (2006). The neurobiology of love. FEBS Letters 581, 25752579.