Jean Decety obtained three advanced master's degrees in 1985 (neuroscience), in 1986 (cognitive psychology), and in 1987 (biomedical engineering science) and was awarded a Ph.D. in 1989 (neurobiology - medicine) from the Université Claude Bernard.

In 2022, Decety was elected as a member of the Academia Europaea, a pan-European Academy of Humanities, Letters, Law, and Sciences, in the Physiology and Neuroscience section.

[5] Together, these findings have been interpreted as a demonstration of functional equivalence between the imagination and the production of action, to the extent that they share the same motor representations underpinned by the same neurophysiological substrate.

[7][8] Decety studies the neurobiological and psychological mechanisms that guide social decision-making, moral reasoning, empathy and sensitivity for justice, as well as how these abilities develop in children, and are shaped by life experiences and group dynamics.

[19] Based on empirical research combining functional neuroimaging (fMRI and EEG), developmental psychology, and individual differences in personality traits, Decety argues that in order to promote justice, it may be more effective to encourage perspective taking and reasoning than emphasizing emotional sharing with the misfortune of others.

[20][21] Decety thinks that the ability to recognize and vicariously experience what another individual is undergoing was a key step forward in the evolution of social behavior, and ultimately, morality.

[25] Recently, drawing on empirical research in evolutionary theory, developmental psychology, social neuroscience, and psychopathy, Jean Decety argued that empathy and morality are neither systematically opposed to one another, nor inevitably complementary.

[28] His work shows that the higher the level of psychopathy, the less neural activity in ventromedial prefrontal cortex in response to perceiving interpersonal harm as well as expressions of physical and emotional pain.

A first study combined measures of socioeconomic status (SES), executive functions, affective sharing, empathy, theory of mind, and moral judgment in predicting altruism in children from the age of 5 to 12 in five large‐scale societies: Canada, China, Turkey, South Africa, and the US.

[35] Results demonstrate that age, gender, SES, and cognitive processes (executive function and theory of mind), but not empathy, were the best predictor of children's generosity in a costly resource allocation game.

The study utilized behavioral measures of punitive tendencies when evaluating interpersonal harm, moral judgment, empathy, and generosity (Dictator Game) in 1,151 children aged 5–12 years sampled from six countries (Canada, China, Jordan, South Africa, Turkey and USA).

Once this error was corrected, as Shariff wrote, "most of the associations they observed with religious affiliation appear to be artifacts of between-country differences, driven primarily by low levels of generosity in Turkey and South Africa.