A human working memory advantage for social network information

Abstract

As a social species, humans live in complexly bounded social groups. In order to navigate these networks, humans rely on a set of social-cognitive processes, including social working memory. Here, we designed a novel network memory task to study working memory for social versus non-social network information across 241 participants (18-65 years) in a tightly controlled, preregistered study. We show that humans demonstrate a working memory advantage for social, relative to non-social, network information. We also observed a self-relevant positivity bias, but an 'other' negativity bias. These findings are interpreted in the context of an evolutionary need to belong to one's social group, to identify risks to one's social safety and to appropriately track one's social status within a complex network of social relationships.

Keywords: depression; social cognition; social networks; working memory.

Figure 1.

Network memory task. The figure illustrates a trial from the social-self condition. In each trial participants are first shown a vignette describing the relationships within the network for 7.5 s, a network diagram of these relationships then appears below the vignette. The diagram is shown for 15–30 s (i.e. participants have the option to proceed with the trial after seeing the diagram for a minimum of 15 s). Lastly, participants are shown three individual connections from the network and are asked if the people/flights shown are friends/operating (social/non-social conditions). Time spent viewing the diagram did not significantly differ (F = 2.11, d.f. = 479.15, p = 0.123 across conditions; non-social: M = 18.46, s.d. = 2.00; social-other: M = 18.68, s.d. = 2.02; social-self: M = 18.50, s.d. = 2.04).

Figure 2.

Network task performance depending on condition. (a) Reaction time performance across task conditions (non-social versus social). Panel (b) Total number of network associations recalled correctly across conditions (non-social versus social). (c) Reaction time performance across task conditions (non-social versus social-other versus social-self). Panel (d) Total number of network associations recalled correctly across conditions (non-social versus social-other versus social-self). RT = average reaction time on correct trials; Accuracy = number of trials correct out of 36 total/condition; Non-Social = trials measuring working memory for non-social relations (i.e. flight paths); Social-Other = trials measuring working memory for social relations in networks including only other individuals; Social-Self = trials measuring working memory for relations in social networks including the self and others; Social = trials measuring working memory for relations collapsed across social-other and social-self trials. *p < 0.05, **p < 0.01, ***p < 0.001.

Figure 3.

Network task performance depending on valence and condition. The figure illustrates the interacting effects of valence (negative versus positive) and condition (non-social versus social-other versus social-self) on reaction time. RT = Average reaction time on correct trials; Non-Social = trials measuring working memory for non-social relations (i.e. flight paths); Social-Other = trials measuring working memory for social relations in networks including only other individuals; Social-Self = trials measuring working memory for relations in social networks including the self and others; Negative = negative valence trials measured working memory for associations between individuals/airports that are not friends/have flights not running; whereas Positive = positive valence trials measured working memory for associations between individuals/airports that are friends/have flights running.