Prevalence, severity and distribution of depression and anxiety symptoms using observational data collected before and nine months into the COVID-19 pandemic.

Background: The COVID-19 pandemic has been accompanied by substantial increases in adverse mental health, particularly among the young. However, it remains unclear to what extent increases in population scores on mental health assessments are due to changes in prevalence, rather than severity of symptoms. Further, it is not obvious that widely used assessments of aggregate symptoms retain their typical interpretation during an event that directly disrupts behavior.

The hidden cost of humanization: Individuating information reduces prosocial behavior toward in-group members.

This paper reports robust experimental evidence that humanization-in the form of individuating information about another's personal preferences-leads to decreased prosocial behavior toward in-group members. Previous research shows that this information increases prosocial behavior toward dehumanized out-group members. The consequences for in-group members, however, are less well understood.

Oversampling of minority categories drives misperceptions of group compositions.

The ability to estimate proportions informs our immediate impressions of social environments (e.g., of the diversity of races or genders within a crowded room).

Deconstructing bias in social preferences reveals groupy and not-groupy behavior.

Group divisions are a continual feature of human history, with biases toward people's own groups shown in both experimental and natural settings. Using a within-subject design, this paper deconstructs group biases to find significant and robust individual differences; some individuals consistently respond to group divisions, while others do not. We examined individual behavior in two treatments in which subjects make pairwise decisions that determine own and others' incomes.

Amount and time exert independent influences on intertemporal choice.

Intertemporal choices involve trade-offs between the value of rewards and the delay before those rewards are experienced. Canonical intertemporal choice models such as hyperbolic discounting assume that reward amount and time until delivery are integrated within each option prior to comparison. An alternative view posits that intertemporal choice reflects attribute-wise processes in which amount and time attributes are compared separately.

Identity economics and the brain: uncovering the mechanisms of social conflict.

Social contexts can have dramatic effects on decisions. When individuals recognize each other as coming from the same social group, they can coordinate their actions towards a common goal. Conversely, information about group differences can lead to conflicts both economic and physical.