The effect of the anchoring bias on the decision making of humans IB Psychology:Standard Level Internal Assessment Candidate: *your six-digit alphanumeric personal code e.g. xyz123* Group: *the personal codes of your group members* Session: May 2022 Date Submitted: 01.06.21 Word count: 2329 Table of contents I. Introduction 3 II. Exploration 5 III. Analysis 7 IV. Evaluation 9 V. Work cited 11 Appendix i-form of consent 12 Appendix ii-Materials(questions) 13 Appendix iii-Debrief 14 Appendix iv-Raw data 15 Appendix v-Mann-Whitney test results 16 VI. VII. VIII. IX. X. 2 Introduction In this technologically developed era, we are subjected to countless sources of information from which we must draw conclusions. This high cognitive load requires our brains to function more efficiently to enable the average human to perform their daily routine effectively. One such way the human brain attempts to increase the efficiency of its functioning is through its unique decision-making process which has been adapted to make decisions and choices based on minimal effort. For example, if you were asked “ what’s 2+3” you would answer with “ 5” without any critical thinking. However, if you were asked “ what’s 19 x 27” you would have to carefully calculate the answer in your head to provide an accurate answer. This efficient thinking mechanism was termed system 1 thinking according to the dual-process model which was developed by Stanovich and West(2000). According to this model of decision making and thinking humans have two distinct modes of thinking termed intuitive thinking(system1 ) and rational thinking (system2). Moreover, Stanovich and West proposed that system 2 is based on careful thought of all possible alternatives for a given problem while system 1 is based on heuristics. A heuristic is an assumption or a simple rule which we use to generate quick responses on changes in our environment and their causations, and form prognoses. We make use of these ‘mental shortcuts’ inorder to make decisions and choices efficiently and effortlessly(cherry, 2021). However, this could also lead to consistent yet somewhat inaccurate patterns of thinking, termed as cognitive biases. One such bias is the anchoring bias, which is a"biased estimate toward an arbitrary value considered by judges before making a numerical estimate" ( Strack and Mussweiler,1997 p 437). For example, a man buys a shirt for 50$. Later he decides to resell his shirt to a customer for 100$. The customer will begin bargaining as he believes 100$ is overpriced, yet he will unintentionally be anchored to the 100$ value. After bargaining with the customer for a while the man decides to sell it for 80$. The customer will be pleased as he will believe that it was an amazing deal as he can pay 20$ less, when in reality he is paying 30$ more. Nevertheless, anchoring bias is essential in the efficiency of our decision making processes as it allows us to make reasonable estimates based on limited information. The anchoring bias was first experimented with by Strack and Mussweiler(1997). The study used 69 German university students who were asked to sit at one of four computer terminals and answer a series of questions. The question was "Did Mahatma Gandhi die before or after the age of X?" The second question was "How old was he when he died?" The suggested age for each terminal was different. The anchor values were implausible low anchor (9); implausible high anchor (140); a plausible low anchor (64); plausible high anchor (79). 3 The results showed that the plausible anchors had a visible effect on participants' estimates, with a mean of 99.6 years for the plausible high anchor and a mean of 67.9 for the plausible low anchor. The implausible high anchor had a lesser effect than the implausible low anchor, with a mean of 66.7 and 50.1 respectively. We decided to replicate this study, however, changing the famous person to Chadwick Boseman, A famous actor whom we assumed to be well known among high school students, and observing the effect of only a plausible high anchor for simplification. Additionally, a control condition was created to observe the thinking and decision making pattern of participants without an anchor since the original study did not attempt to observe this. We aimed to observe the effect a high plausible anchor has on the estimation of the age of death of Chadwick Boseman among high school students. This is because it would be of high interest to identify if the anchoring bias affects people who already have a general understanding or knowledge regarding a specific situation, incident or event. Although the original study used a famous person (Mahatma Gandhi) as a part of their experimentation it could be inferred that at the time the experiment was carried out there would have been a slim chance of the German participants to know about the existence or a general idea of such a person. Null hypothesis: The difference between the estimated age of death given by the participants subjected to the high plausible anchor and the participants in the control condition will be insignificant. Research hypothesis: The age estimated by the participants subjected to the high plausible anchor will be higher than that of the control group. The independent variable(IV) will be the value assigned as the high plausible anchor while the dependent variable (DV) is the estimated age of death of Chadwick Boseman. 4 Exploration This experiment used an independent measures design, which is a design technique where in each condition of the experiment, different people are employed. Additionally random allocation is utilized to allocate a condition for each participant(Independent Groups | Psychology, 2018), since it ensures that each participant has an equal probability of being assigned to one of two groups. The reason this technique was used is that asking the control question and the anchor question from the same participant would be redundant as they would give the same answer for both questions thus making it impossible to observe the effect of the anchor on their thinking and decision making. Hence we randomly allocated the participants to a control condition (participants received the control question) and an anchor condition (participants received the question with the high plausible anchor) by shuffling the question set before distribution and handing each participant the question sheet on the top of the set to minimize the effects of individual differences of participants on the estimation of the age of death of Chadwick Boseman. The participants for the experiment were acquired through opportunity sampling, which is a sampling technique where members of a population of interest are recruited by asking if they would like to take part in research(Mcleod, 2019). Using this technique we recruited 28 high school students of ages 17 to 19 who did not take psychology as a subject from a library at an international school in Singapore. The reason behind this selection was because the original study recruited university students, which suggests that the participants were directly involved in higher education and were of early age and thus it would be beneficial to use similar participants in the recreation of the original study. Moreover, recruiting participants who did not take psychology reduced the chance of demand characteristics which could reduce the reliability of the results. Finally, We made sure to ask all students if they would like to participate starting from the entrance of the library until the required limit of participants were met to reduce selection bias, which is a kind of error commonly seen during opportunity sampling, when the researcher selects the participants going to be studied(Selection Bias, 2014). The most significant variable subjected to control was the time the participants were allowed to answer the question. The participants were given only 20 seconds to read and answer the question. This was done to confirm that the participant will use their system 1 thinking rather than their system 2 thinking. Additionally, Chadwick Boseman was used as the famous person throughout the experiment to minimize the effect of individual differences which could occur as a result of using multiple famous people throughout the experiment. The nature of the question provided to each condition of this experiment was similar to the original study except the famous person used to strengthen the extent to which the original study was replicated(Appendix ii). The question received by the anchor condition participants 5 was, “ Did Chadwick Boseman die before or after the age of 90”, while the question received by the control condition participants received, “At what age did Chadwick Boseman die?” The following steps were taken to perform the experiment 1. The questions which were on strips of paper were stapled to the back of each consent form (see appendix i) 2. The consent forms were then shuffled to randomize the questions given to the participant. (as the question determines the condition to which the participant would fall under) 3. The participants were handed the randomized consent forms and were asked to sign them if they were willing to participate 4. If the participant signed the form, directions were provided on how to do the activity, 5. The participant was asked to turn the paper over and answer the question attached at the back in 10 seconds. 6. The consent forms were collected and a debrief form(see appendix iii) was handed to the participants 6 Analysis Anchor condition Median of tendency(MOCT) central 43.0 Median of dispersion(MOD) 3 Control condition 42.0 5.25 The data we collected was ordinal (Appendix iv), categorical data with a set order or scale. Hence the median of the collected data used as the MOCT while the semi interquartile range was used as the MOD. As seen above the MOCT for the participants in the anchor condition is slightly greater than that of the participants of the control condition with values 43.0 and 42.0 respectively. However, In terms of the MOD, control condition participants received a value greater than the anchor condition participants with values 5.25 and 3 respectively. This suggests that even though the anchor condition was introduced to a numerical anchor it had a near negligible impact on the relevant estimates of age when compared with the control condition which did not receive a numerical anchor. However, it can be implied through the values of the MOD of both conditions that the reason the variability of estimates of anchor condition is less than the control condition because of the influence of the anchor as it suggests that the estimates provided by the participants in the anchor condition are pulled towards a certain value rather than the control condition participants thus causing minimal dispersion of estimates. 7 A Mann-Whitney U test indicated that there was no significant difference between age estimates for the anchor condition (Median = 43) and the control condition (Median = 42), U = 73, p = 0.28774 (Appendix v). To reject the null hypothesis p ≤ 0.05. However, the p-value arrived upon through the test is much larger than the required range of p values to reject the null hypothesis. Thus it can be concluded that there is no significance between the control condition and the anchor condition, which suggests that the anchor provided to the participants of the anchor condition has had almost no effect on their estimations of the age of death of Chadwick Boseman thus confirming our null hypothesis and disproving our research hypothesis. 8 Evaluation Even Though our results do not agree with the original study it can be assumed that this might have been a result of using a famous figure well known among the participants which resulted in the anchor value being inefficient as the participants would have a stronger understanding of him, rather than the participants of the original study who might have not known Mahatma Gandhi. However, we might have been able to observe the effects of the anchor if the anchor value was more plausible ( 60-70). Regardless, it would be an interesting extension to observe the extent to which an anchor could influence someone's decision making based on the level of knowledge/understanding the person has regarding the specific situation. One strength received through the use of independent measures design is that we were able to reduce order effects which could have arisen if we had allowed each participant to take part in both control and anchor conditions because that will make the participants incline to give the same age estimates for both questions due to the similarity of the questions. However, one constraint we faced during the experiment was the lack of participants we were able to recruit(28). Since the design is independent measures this could have led to possible individual differences of participants which could have influenced the results. Although this issue could have been solved through the use of a different research design such as repeated measures, we would arrive at the same issue stated above where the participants will give the same age estimate for the 2 questions in the 2 conditions due to their near similarity. Opportunity sampling turned out to be extremely beneficial to us in terms of the efficiency in which participants were able to be recruited, considering the time constraints we had to experiment (1 hour), however, this sampling technique could have led to selection bias which could have led to the unreliability of our results even though steps were taken to limit them (mentioned in exploration). This bias would have been avoided if volunteer sampling was used instead as this would prevent us from choosing participants thus preventing our implicit biases from influencing our selection of participants. The procedure carried out during the experiment was sound, especially the standardized directions as the participants were able to experiment without uncertainty and hesitation. However, one major drawback of the experiment was the time allocated for the participants to answer the question( 20 s) as it might have given enough time for the participants to switch from system1 thinking to system2 thinking thus causing them to answer the question based on careful thought rather than heuristics thus causing the introduced anchor(in the anchor condition) to be ineffective. Therefore it would have been beneficial to limit the time to answer the question to 10s. 9 To conclude, the p-value received through the Mann-Whitney U test carried out on the results gained by the experiment is much greater than 0.05 suggesting that the control condition estimates and the anchor condition estimates have no significance, therefore, retaining the null hypothesis and hence justifying that the difference between the estimated age of death given by the participants subjected to the high plausible anchor and the participants in the control condition is insignificant. 10 Work cited cherry, K. E. N. D. R. A. (2021). How Heuristics Help You Make Quick Decisions. VerywellMind.https://www.verywellmind.com/what-is-a-heuristic-2795235#:%7E:text=A%20heuristi c%20is%20a%20mental,their%20next%20course%20of%20action. Strack, F., & Mussweiler, T. (1997). Explaining the enigmatic anchoring effect: Mechanisms of selective accessibility. Journal of Personality and Social Psychology, 73(3), 437–446. https://doi.org/10.1037/0022-3514.73.3.437 Independent Groups |Psychology. (2018). Tutor2u. https://www.tutor2u.net/psychology/topics/independent-groups-design#:%7E:text=Independe nt%20groups%20design%20is%20an,each%20condition%20of%20the%20experiment Mcleod, S. (2019). Sampling Methods | Simply Psychology. SimplyPsychology. https://www.simplypsychology.org/sampling.html#:%7E:text=Opportunity%20Sampling&te xt=An%20opportunity%20sample%20is%20obtained,coming%20out%20of%20the%20librar y Selection bias. (2014). Institute for Work https://www.iwh.on.ca/what-researchers-mean-by/selection-bias and Health. Blog, F. (2019, October 10). What is Ordinal Data? Examples, Variables & Analysis. Formpl. https://www.formpl.us/blog/ordinal-data Stangroom, J. E. R. E. M. Y. (2021). Social Science Statistics. Socscistatistics. https://www.socscistatistics.com/ 11 Appendix i - form of consent Study Title: Observation Of The Effects Anchoring Bias Through The Replication Of Strack & Mussweiler Experimenter(s): DHANA KODITUWAKKU, JAMES ILLINGWORTH, RANDEV RANJIT Description Of The Experiment: You will be required to guess the age of a famous individual. To participate in this research study, you must give informed consent. By signing these informed consent statements, you indicate that you understand the nature of the research study and your role in that research and agree to participate in the study. Please consider the following points before signing: - - I understand that I am participating in psychological research; I understand that my identity will not be linked with my data and that all of the information I provide will remain confidential; I understand that I will be provided with an explanation of the research I participated in and will be given the name and telephone number of an individual to contact if I have questions about the study. I understand that participation in research is not required, is voluntary and that after any individual research project has begun, I may refuse to participate further without any obstruction. By signing this form, I am stating that I am 16 or older and that I understand the above information and consent to participate in this study being conducted at UWC Dover. Signature:____________________________________________ Date:________________ 12 Appendix ii-questions of the conditions Control condition question:- At what age did Chadwick Boseman die? Anchor question condition:- Did Chadwick Boseman die before the age of 90? 13 Appendix iii-Debrief 14 Appendix iv-Raw data control anchor 32 30 34 37 34 39 37 40 38 41 42 42 42 43 42 44 43 44 45 45 47 46 47 48 50 60 15 Appendix v-Mann-Whitney U test results 16 17 18