neuroimaging research suggests that reward processing is highly relative , which is in agreement with social psychological findings that make comparison one of the central mechanisms of social cognition . yet , what are the cerebral processes that enable us to compare ourselves to other people ? does social comparison rely on the same brain network as other kinds of comparative judgments or do they engage specific systems ? extensive research in cognitive neuroscience has identified a network that may be responsible for the representation and comparison of a wide range of nonsocial magnitudes . this network encompasses the intraparietal sulcus ( ips ) as well as areas of the prefrontal cortex 59 . the activity of this network is modulated by a distance effect : the closer two magnitudes ( e.g. , two numbers ) , the more difficult the comparison and the greater the activity of this frontoparietal network 60,61 . this network , and in particular the ips , is recruited by comparisons of numbers presented in different formats ( e.g. , digits , words ) , size , dot patterns , line lengths , magnitudes of angles , luminance , and money rewards 6067 . so far , the cerebral mechanisms that enable us to compare ourselves to others have received the attention of only one study 68 . in this fmri experiment , participants were asked to compare their own height or intelligence with that of individuals they personally know . conversely , intelligence comparisons recruited to a larger extent the mpfc and other areas dedicated to the attribution of mental states to others . they may reflect differences in the nature of the information retrieved in memory for the comparison ( physical vs. psychological information ) or they may result from differences in the comparative process itself ( for a discussion of this issue , see kedia et al . one would need to focus on the comparative process and exclude other perceptual or inferential mechanisms . to date , this approach has not been adopted for self  other comparisons , but it has been applied to other  other comparisons . 69 relied on this method to investigate the neural networks recruited by the comparison of two celebrities height ( who is taller : elvis or bush ? ) and intelligence ( who is more intelligent : hanks or einstein ? ) . in addition to these comparative conditions , the researchers used two control conditions , in which participants had to indicate whether one of the two celebrities was a politician or a musician . this study did not find any activation in the ips , but rather showed the activity of a network composed of the mpfc and other regions important for social information processing . this network was recruited by both intelligence and height comparisons compared with the control conditions , although activations were stronger for intelligence than height comparisons . this led the authors to conclude that person comparisons rely on different neural comparative systems than comparisons of other categories of objects . this study does , however , entail confounds that would need to be controlled to interpret these results . first , there was no check to assess whether participants knew the celebrities height and intelligence and thus had all necessary information to perform the comparisons . second , the challenge of using a control condition approach is the choice of an appropriate control condition . a good control condition should notably have the same level of difficulty as the conditions of interest , which was not the case in lindner et al.s 69 study , in which response times were shorter in the control condition than in the comparative ones . moreover , the control condition should not involve any kind of comparison , which is difficult , given that comparisons are ubiquitous ( categorizing a person as a politician or a musician does involve a comparison between the target to categorize and the musician and politician group categories 70,71 ) . this other approach makes use of the distance effect , as commonly done to study magnitude comparison and numerical cognition . some social neuroscientists have indeed reflected that if personal characteristics are similarly represented and compared in the brain as nonsocial magnitudes , they should elicit similar effects and these effects should engage the same neural networks . for example , if person comparisons were to follow a distance effect , one would expect comparisons of persons close on a certain characteristic ( e.g. , of similar attractiveness ) to be more difficult and engage to a greater extent the frontoparietal network associated with nonsocial comparisons . two articles have already tested this hypothesis for comparisons of height , attractiveness 72 , and social status 73 . both studies found behavioral distance effects and , in both studies , these distance effects engaged the ips ( fig . the beauty and height distance effects overlap in the right and left intraparietal sulcus ( ips ) , the dmpfc , and the cerebellum , four regions known for their involvement in comparisons of numbers and simple nonsocial magnitudes . reprinted from kedia et al . 72 with permission from oxford university press . so in order to publish this adaptation , authorization must be obtained both from the owner of the copyright in the original work and from the owner of copyright in the translation or adaptation . the finding that comparisons of personal characteristics recruit the same comparative network as nonsocial comparisons does not , however , imply that different kinds of judgments engage strictly identical brain regions . for example , height comparisons elicited overall more ips activity than attractiveness comparisons and attractiveness comparisons elicited overall greater activity in the fusiform gyrus , a region of the occipital cortex dedicated to face perception and recognition 72 . however , the distance effects remained unaffected by the compared dimension , which suggests that the comparative process was the same . this model assumes that perceptual and evaluative processes vary depending on the compared dimension : facial characteristics such as attractiveness , for example , would recruit the fusiform gyrus whereas body dimensions , such as height , may involve the parietal cortex . this model also assumes that the actual comparison of the extracted magnitudes relies on a common frontoparietal comparative system ( fig . dlpfc , dorsolateral prefrontal cortex ; ips , intraparietal sulcus ; mofc , medial orbitofrontal cortex ; mpfc , medial prefrontal cortex . this model could be tested by investigating the time course of comparison processing using erps . the model would then predict differences in early perceptual processes ( reflected for example by differences in the n170 , the face - sensitive erp component ) , but no distance effect of these neural markers . previous erp studies have observed that the distance effect for numbers  whether presented in words or arabic digits  emerges at around 200  ms after stimulus onset 74 . one could thus also use electroencephalography to assess whether person comparisons , which involve more complex stimuli than numbers , follow a similar time course as numbers or whether they occur at a later latency . research on the underlying mechanisms of social comparison points to a frontoparietal network also recruited by nonsocial comparisons . the studies that have identified this network relied on comparisons of attractiveness , height , and social status 72,73 . further investigation is needed to test whether this frontoparietal system is also involved in comparisons of complex mental states such as trustworthiness or intelligence . future research should also investigate whether this network is recruited by spontaneous comparisons , that is , by situations in which participants compare themselves to others even though they were not explicitly instructed to do so ( see paradigms described in the first section and fig . , a recent fmri experiment 75 suggests that the ips may be recruited by spontaneous comparisons of financial status . participants of this study were asked to form an impression of targets with high or low annual salaries . results showed that the ips was modulated by the financial status of the targets even though participants were not explicitly instructed to evaluate it . this higher ips activity for low than for high financial statuses can be interpreted as a distance effect : participants may have spontaneously used their own financial status as a comparison standard to judge those of the targets , and the fact that participants incomes were closer to the low than to the high financial statuses may have created an effect of distance . this interpretation is , however , speculative , given that the study did not actually measure the distance between participants and targets financial situations and its effect on the ips . the role of the ips in spontaneous social comparisons thus still remains to be determined by more direct investigations . in general , the involvement of the comparative frontoparietal network should be tested for a broader range of self  other comparisons : it is still unclear whether self  other comparisons involve a distance effect and whether this distance effect relies on the activity of the same frontoparietal network as other  other comparisons . when comparing themselves with others , people show biases that may influence comparative brain processes . for example , people have a tendency to overestimate their qualities and to consider themselves as better than average 76 . at the brain level , this biased evaluation occurs with decreased activation of the medial orbitofrontal cortex ( mofc ; see fig . 5 and beer and hughes 77 ) . in this context , the mofc may enable one to correct one s initial biased evaluation and shift from one s natural response tendency 7880 . so far , the question of whether ( and how ) self - related biases influence comparison processes has not received much attention . do self  other comparisons rely on the same frontoparietal network as other  other and nonsocial comparisons ? if so , is this network modulated by self - related brain regions , such as the mofc ? or do self other comparisons rather engage brain networks that are distinct from those supporting other kinds of comparisons ? future research should identify the different networks involved in self  other comparisons and analyze how they interact with each other . people tend to consider that they possess more desirable personalities than others . at the brain level , this above - average effect comes with a reduction in medial orbitofrontal cortex activity . so in order to publish this adaptation , authorization must be obtained both from the owner of the copyright in the original work and from the owner of copyright in the translation or adaptation . extensive research in cognitive neuroscience has identified a network that may be responsible for the representation and comparison of a wide range of nonsocial magnitudes . this network encompasses the intraparietal sulcus ( ips ) as well as areas of the prefrontal cortex 59 . the activity of this network is modulated by a distance effect : the closer two magnitudes ( e.g. , two numbers ) , the more difficult the comparison and the greater the activity of this frontoparietal network 60,61 . this network , and in particular the ips , is recruited by comparisons of numbers presented in different formats ( e.g. , digits , words ) , size , dot patterns , line lengths , magnitudes of angles , luminance , and money rewards 6067 . so far , the cerebral mechanisms that enable us to compare ourselves to others have received the attention of only one study 68 . in this fmri experiment , participants were asked to compare their own height or intelligence with that of individuals they personally know . conversely , intelligence comparisons recruited to a larger extent the mpfc and other areas dedicated to the attribution of mental states to others . they may reflect differences in the nature of the information retrieved in memory for the comparison ( physical vs. psychological information ) or they may result from differences in the comparative process itself ( for a discussion of this issue , see kedia et al . one would need to focus on the comparative process and exclude other perceptual or inferential mechanisms . to date , this approach has not been adopted for self  other comparisons , but it has been applied to other  other comparisons . 69 relied on this method to investigate the neural networks recruited by the comparison of two celebrities height ( who is taller : elvis or bush ? ) and intelligence ( who is more intelligent : hanks or einstein ? ) . in addition to these comparative conditions , the researchers used two control conditions , in which participants had to indicate whether one of the two celebrities was a politician or a musician . this study did not find any activation in the ips , but rather showed the activity of a network composed of the mpfc and other regions important for social information processing . this network was recruited by both intelligence and height comparisons compared with the control conditions , although activations were stronger for intelligence than height comparisons . this led the authors to conclude that person comparisons rely on different neural comparative systems than comparisons of other categories of objects . this study does , however , entail confounds that would need to be controlled to interpret these results . first , there was no check to assess whether participants knew the celebrities height and intelligence and thus had all necessary information to perform the comparisons . second , the challenge of using a control condition approach is the choice of an appropriate control condition . a good control condition should notably have the same level of difficulty as the conditions of interest , which was not the case in lindner et al.s 69 study , in which response times were shorter in the control condition than in the comparative ones . moreover , the control condition should not involve any kind of comparison , which is difficult , given that comparisons are ubiquitous ( categorizing a person as a politician or a musician does involve a comparison between the target to categorize and the musician and politician group categories 70,71 ) . this other approach makes use of the distance effect , as commonly done to study magnitude comparison and numerical cognition . some social neuroscientists have indeed reflected that if personal characteristics are similarly represented and compared in the brain as nonsocial magnitudes , they should elicit similar effects and these effects should engage the same neural networks . for example , if person comparisons were to follow a distance effect , one would expect comparisons of persons close on a certain characteristic ( e.g. , of similar attractiveness ) to be more difficult and engage to a greater extent the frontoparietal network associated with nonsocial comparisons . two articles have already tested this hypothesis for comparisons of height , attractiveness 72 , and social status 73 . both studies found behavioral distance effects and , in both studies , these distance effects engaged the ips ( fig . ( b ) the beauty and height distance effects overlap in the right and left intraparietal sulcus ( ips ) , the dmpfc , and the cerebellum , four regions known for their involvement in comparisons of numbers and simple nonsocial magnitudes . reprinted from kedia et al . so in order to publish this adaptation , authorization must be obtained both from the owner of the copyright in the original work and from the owner of copyright in the translation or adaptation . the finding that comparisons of personal characteristics recruit the same comparative network as nonsocial comparisons does not , however , imply that different kinds of judgments engage strictly identical brain regions . for example , height comparisons elicited overall more ips activity than attractiveness comparisons and attractiveness comparisons elicited overall greater activity in the fusiform gyrus , a region of the occipital cortex dedicated to face perception and recognition 72 . however , the distance effects remained unaffected by the compared dimension , which suggests that the comparative process was the same . this model assumes that perceptual and evaluative processes vary depending on the compared dimension : facial characteristics such as attractiveness , for example , would recruit the fusiform gyrus whereas body dimensions , such as height , may involve the parietal cortex . this model also assumes that the actual comparison of the extracted magnitudes relies on a common frontoparietal comparative system ( fig . dlpfc , dorsolateral prefrontal cortex ; ips , intraparietal sulcus ; mofc , medial orbitofrontal cortex ; mpfc , medial prefrontal cortex . this model could be tested by investigating the time course of comparison processing using erps . the model would then predict differences in early perceptual processes ( reflected for example by differences in the n170 , the face - sensitive erp component ) , but no distance effect of these neural markers . previous erp studies have observed that the distance effect for numbers  whether presented in words or arabic digits  emerges at around 200  ms after stimulus onset 74 . one could thus also use electroencephalography to assess whether person comparisons , which involve more complex stimuli than numbers , follow a similar time course as numbers or whether they occur at a later latency . research on the underlying mechanisms of social comparison points to a frontoparietal network also recruited by nonsocial comparisons . the studies that have identified this network relied on comparisons of attractiveness , height , and social status 72,73 . further investigation is needed to test whether this frontoparietal system is also involved in comparisons of complex mental states such as trustworthiness or intelligence . future research should also investigate whether this network is recruited by spontaneous comparisons , that is , by situations in which participants compare themselves to others even though they were not explicitly instructed to do so ( see paradigms described in the first section and fig . a recent fmri experiment 75 suggests that the ips may be recruited by spontaneous comparisons of financial status . participants of this study were asked to form an impression of targets with high or low annual salaries . results showed that the ips was modulated by the financial status of the targets even though participants were not explicitly instructed to evaluate it . this higher ips activity for low than for high financial statuses can be interpreted as a distance effect : participants may have spontaneously used their own financial status as a comparison standard to judge those of the targets , and the fact that participants incomes were closer to the low than to the high financial statuses may have created an effect of distance . this interpretation is , however , speculative , given that the study did not actually measure the distance between participants and targets financial situations and its effect on the ips . the role of the ips in spontaneous social comparisons thus still remains to be determined by more direct investigations . in general , the involvement of the comparative frontoparietal network should be tested for a broader range of self  other comparisons : it is still unclear whether self  other comparisons involve a distance effect and whether this distance effect relies on the activity of the same frontoparietal network as other  other comparisons . when comparing themselves with others , people show biases that may influence comparative brain processes . for example , people have a tendency to overestimate their qualities and to consider themselves as better than average 76 . at the brain level , this biased evaluation occurs with decreased activation of the medial orbitofrontal cortex ( mofc ; see fig . 5 and beer and hughes 77 ) . in this context , the mofc may enable one to correct one s initial biased evaluation and shift from one s natural response tendency 7880 . so far , the question of whether ( and how ) self - related biases influence comparison processes has not received much attention . do self  other comparisons rely on the same frontoparietal network as other  other and nonsocial comparisons ? if so , is this network modulated by self - related brain regions , such as the mofc ? or do self other comparisons rather engage brain networks that are distinct from those supporting other kinds of comparisons ? future research should identify the different networks involved in self  other comparisons and analyze how they interact with each other . people tend to consider that they possess more desirable personalities than others . at the brain level , this above - average effect comes with a reduction in medial orbitofrontal cortex activity . so in order to publish this adaptation , authorization must be obtained both from the owner of the copyright in the original work and from the owner of copyright in the translation or adaptation . social comparison constitutes a fundamental social cognitive process and is the focus of one of the major theories in social psychology . this research field has recently begun to spread out to neuroscience , but many questions still remain to be explored . so far , neuroimaging studies on social comparison have either focused on the influence of social comparison on the reward system in gaming situations or on the cognitive and neural mechanisms supporting explicit comparisons . these two research areas have not yet , however , been linked to each other and the question of the connection between the comparative and reward systems still remains to be elucidated . these analyses rely on fmri data to characterize the interactions between spatially remote brain regions and could , thus , be used to explore the correlation between the comparative and reward brain systems . this question could also be addressed in the context of the selective accessibility model 15 . this social cognitive model posits two ways of comparing oneself with others . on the one hand , one can seek similarities between oneself and the comparison standard and assimilate to this person ; on the other hand , one can focus on the dissimilarities and contrast away from the standard . these two comparative processes have opposing consequences . assimilation to an upward standard ( e.g. , former race car driver niki lauda ) leads to a positive self - evaluation ( i have high athletic abilities ) , whereas contrast leads to a negative self - evaluation ( i have poor athletic abilities ) . at the brain level , assimilation and contrast comparison mindsets may reverse the effect of social comparison on the reward system and change the sign of social prediction errors . for example , participants engaging in similarity testing may show higher levels of ventral striatal activity when exposed to a more rewarded co - player . this hypothesis remains to be tested and the effects of similarity and dissimilarity testing on the comparative and affective systems should be explored . the social psychology literature suggests that the mechanisms underlying social comparison and their connection to the reward system are likely to be modulated by several factors . the standard chosen for the comparison is of primary importance 82,83 . in experimental settings , comparison standards have usually been external persons ( e.g. , a familiar other , a celebrity , a confederate , or another participant ) but it would also be interesting to consider internal standards ( e.g. , ideal , past , or future selves , societal norms ) . comparisons with internal standards are frequently used in everyday life to evaluate or motivate oneself and improve one s performance 84,85 . for example , people with chronic medical problems tend to engage in comparisons with their past selves and to consider their present condition as better than it used to be at the beginning of their disease 86 . it is , however , still unclear whether comparisons with internal standards recruit the same brain networks as comparisons with external ones . previous research in social psychology has also shown how the characteristics of the standard influence the comparison process : people tend to assimilate  rather than contrast away  to similar , familiar , moderate , and psychologically close standards as well as to members of their ingroup 15,87,88 . how these characteristics influence the comparative and emotional brain systems would be a question of great interest . besides the comparison standard , social comparisons also depend on personality and cultural influences . although the desire to compare oneself to others is universal , some people are more prone to engage in social comparisons than others . individuals high in social comparison orientation ( sco ) engage in social comparison more often and they are also more affected by it 89 . people high in sco tend to be more self - conscious and show lower self - esteem and higher neuroticism 90 . in a similar vein , individuals who are prone to social comparisons are more interested in what others feel and need and show higher levels of empathy 90 . this suggests that sco does not merely reflect a competitive mindset but rather an interdependent self . it is therefore not surprising that higher sco has been observed in women compared with men and in cultures high on interdependence and power distance belief 93 . in accordance with these observations , a recent fmri experiment reports that korean participants ( representing an interdependent culture in the study ) show a stronger modulation of the vs by social comparisons than american participants ( representing an independent culture 31 ) . on the basis of the general differences in sco between men and women however , neuroimaging studies investigating the neural correlates of social comparison have not observed any significant difference in vs activity between men and women 2628 . it is , however , important to note that all these studies are limited in that they relied on small samples of participants ( between eight and 38 of each sex ) and may lack the statistical power to show significant differences . future experiments involving larger samples should thus clarify whether sex differences in social comparison behavior are associated with identifiable neural differences . social comparisons are involved in a wide range of social cognitive processes spanning from person perception to attitudes and stereotyping . the discovery of the neural correlates of social comparison would enable researchers to evaluate the role played by comparison in social cognitive processes and as a consequence to further elucidate the neural mechanisms of social cognition .
whenever we interact with others , we judge them and whenever we make such judgments , we compare them with ourselves , other people , or internalized standards . 
 countless social psychological experiments have shown that comparative thinking plays a ubiquitous role in person perception and social cognition as a whole . 
 the topic of social comparison has recently aroused the interest of social neuroscientists , who have begun to investigate its neural underpinnings . 
 the present article provides an overview of these neuroimaging and electrophysiological studies . 
 we discuss recent findings on the consequences of social comparison on the brain processing of outcomes and highlight the role of the brain s reward system . 
 moreover , we analyze the relationship between the brain networks involved in social comparisons and those active during other forms of cognitive and perceptual comparison . 
 finally , we discuss potential future questions that research on the neural correlates of social comparison could address .