We report data from an online experiment, which allow us to study whether generosity has changed during the early Covid-19 pandemic. We have gathered data from Spanish participants over a six-day period in which Covid-19-associated deaths in Spain, one of the most affected countries, increased...

The use of hypothetical instead of real decision-making incentives remains under debate after decades of economic experiments. Standard incentivized experiments involve substantial monetary costs due to participants’ earnings and often logistic costs as well. In time preferences experiments,...

Prenatal exposure to hormones, and to sex hormones in particular, exerts organizational effects on the brain and these have observable behavioral correlates in adult life. There are reasons to expect that social behaviors—which are fundamental for the evolutionary success of humans—might be...

Prenatal exposure to hormones, and to sex hormones in particular, exerts organizational effects on the brain and these have observable behavioral correlates in adult life. There are reasons to expect that social behaviors—which are fundamental for the evolutionary success of humans—might be...

Prenatal exposure to hormones, and to sex hormones in particular, exerts organizational effects on the brain and these have observable behavioral correlates in adult life. There are reasons to expect that social behaviors—which are fundamental for the evolutionary success of humans—might be...

It is documented that fetal exposure to sexual hormones has long lasting effects on human behavior. The second-to-fourth digit ratio (DR) is a putative marker for prenatal exposure to testosterone (compared to estrogens) while in uterus, with higher relative exposure to testosterone resulting in...

There is an intense debate whether decision making under uncertainty is partially driven by cognitive abilities. The critical issue is whether choices arising from subjects with lower cognitive abilities are more likely driven by errors or lack of understanding than pure preferences for risk....

Humans often punish non-cooperators in one-shot interactions among genetically-unrelated individuals. So-called altruistic punishment poses an evolutionary puzzle because it enforces a cooperation norm that benefits the whole group, but is costly for the punisher. Under the “big mistake” (or...

Over the past few decades obesity has become one of the largest public policy concerns among the adult population in the developed world. Obesity and overweight are hypothesized to affect individuals’ sociability through a number of channels, including discrimination and low self-esteem....

Children as young as 3-4 years are already concerned about inequality and declare that equality is a norm that should be followed1. From 3 to 8 years they develop a strong preference for equality, which is typically reflected in both “envy” and “compassion”2,3, that is, aversion to...