Anchoring Effect: The Type Of Anchor And The Effect Of Genes

Anchoring effect,which was proposed by Tversky and Kahneman in 1974,is a famous cognitive bias that occurs in decision making.Anchoring effect refers to the phenomenon that the result of an individual's judgment or decision-making is biased toward the external irrelevant information(the “anchor”)which was previously presented.For example,in the price negotiation,the initial offer is often regarded as the starting point for subsequent negotiation,and the final price is often close to the initial offer.Apart from the condition mentioned above,anchoring effect can also be found in probability estimation,price judgment,answering general knowledge questions and many other fields.Many theories have been proposed to explain the anchoring effect,and the“anchoring and insufficient adjustment” theory was a widely recognized theory.Specifically,when individuals encounter an anchor point and then need to estimate,they may start from the anchor point and make a series of incremental adjustments until they feel the correct answer.Given that adjustment consumes attention and energy,people usually stop adjustment too quickly and get an estimate near the anchor.To put it another way,impulsivity generates insufficient adjustment and anchoring effect.However,there is still no uniform answer to the mechanism of anchoring effect,and the factors that affect the strength of anchoring effect are still need to be explored.So far,the hundreds of studies,which have investigated anchoring effects from various angles,showed its robustness.We aims to investigate the influence of the decision-making object and subject on the anchoring effect.We choose the gene locus and the type of anchor respectively as specific point of them for research,which are relatively novel.After reviewing previous studies we found that:(1)Most(perhaps all)studies on anchoring effect only adopted single-point anchors(e.g."Do you want to buy a dryer with a price higher or lower than 800 yuan?").In fact,another kind of anchor which is also common in actual life is the interval anchor(e.g."Do you want to buy a dryer with a price within 600-1000 yuan?").No study had investigated whether these two kinds of anchors can produce same strength of anchoring effect;(2)Studies have explored the influence of genes on endowment effect and loss aversion in decision-making.However,previous studies on anchoring effect focus on behavioral study,and no study has explored the influence of genes on anchoring effect.The question of whether genes modulate anchoring effect still awaits an answer.To answer the two questions mentioned above,we designed these two studies.The study 1 of this article aims to verify the anchoring effect of single-point anchors and interval anchors,and investigate the difference in anchoring effect between them.In this study,we conducted three experiments(43,40 and 36 subjects were recruited in experiment 1,2 and 3 respectively)with perceptual estimation questions,world knowledge questions,and price judgment questions respectively to answer the above questions.All these experiments adopted the standard anchoring paradigm,and in each trial of these experiments subjects needed to answer a comparative judgement question and a quantity-estimate question.The anchoring effect is extremely significant for both single-point anchors and interval anchors in each experiment,but no significant difference was found between the anchoring effect of these two kinds of anchors in any experiment.The study 2 of this article,which consists of behavioral experiments and genetic experiments,aims to explore whether genes modulate anchoring effects.376 participants attended this study,they should first complete the behavior experiments,and then provide their saliva for the genetic experiments.We chose the cannabinoid receptor 1(CNR1)gene single nucleotide polymorphism rs806379 to investigate the influence of genes on anchoring effects.The reasons are as follows: CNR1 is a candidate gene for attention deficit/hyperactivity disorder,especially the phenotype associated with drug abuse.Moreover,it has been shown that the AA genotype of rs806379 is associated with enhanced impulsivity,and impulsivity may give rise to anchoring effect.We found that:(1)As revealed in the results of the behavioral experiments,the anchoring effect in our experiment was very strong,which is consistent with previous findings;(2)As revealed in the results of the genetic experiments,subjects with AA genotype of rs806379 showed stronger anchoring effect than those with the T allele(AT genotype in this study).In summary,this is the first study that compared the anchoring effect of single-point anchors and interval anchors and provided the initial evidence that the anchoring effect of interval anchors can be as powerful as that of single-point anchors,which extended the research scope of anchoring effect.In addition,as the first study that explored anchoring effect from the genetic perspective,our findings suggested that nature plays a role in anchoring effect.