The article discusses and analyzes data from several economic experiments in a household survey with mothers of preschool children. The researchers measured competitiveness by giving the subjects the choice between competing in a tournament or receiving a piece rate for a real effort task. The subjects also participated in lottery choices, which enabled the researchers to assess their risk preferences. The relationship between social preferences and competitiveness in the sample of mothers of preschool children was analyzed. The hypothesis that egalitarian subjects aren't as likely to self-select into competitive environments, which can produce winners and losers, was tested. A negative relationship between egalitarian choices and self-selection into competition was found.

Working-memory (WM) capacity is a key component of a wide range of cognitive and noncognitive skills—such as fluid IQ, math, reading, and inhibitory control—but can WM training improve these skills? Here, we examine the causal impact of WM training embedded in regular school teaching, using a randomized educational intervention with 6–7-year-old children. We find substantial gains in WM capacity and document positive spillover effects on geometry, fluid IQ, and inhibitory control. Three years later, treated children are 16 percentage points more likely to enter an advanced secondary school track.