Developmental foundations of understanding others’ needs – Evidence from human infants across populations and great apes

• In Event: Do young children and non-human primates care about other people’s needs?

Abstract

Human infants understand others’ need for help already from around 9-months-of-age, well before they begin to appropriately respond to those needs through actively helping (Köster et al., 2016). These initial findings from German children have since been replicated in a Japanese population, which showed an understanding of others needs at 10- and 16-months-of-age (Köster et al., 2019). This latter study also showed that the transition from understanding others’ needs to acting prosocially is promoted by infants’ developing motor and social interaction skills at 16-months-of-age.
Here, we extend these former studies in two important ways. First, we present the results of an independent replication with a sample from the US, providing evidence for an understand of others’ needs in infants from a third study population. Second, we present the adaptation of the original paradigm to study the understanding of others’ needs in our closest living relatives, the great apes.
In the first study, we applied the experimental conditions of the original eye-tracking paradigm (Figure 1A) in a final sample of N = 29 18-month-old infants. The infants saw a character in need of help but unable to reach its goal because of an obstacle along with a second character who was able to achieve a goal on its own. When a third individual (a helper) initiated an action, the infants expected the helper to help the character in need. This was indicated by their anticipatory looking to the character in need, t(28) = 3.24, p = .003 (Figure 1B). However, we found no evidence in their looking times; namely, infants did not look longer at the screen if the helper helped the character not in need.
In a second conceptually-related study, we developed an eye-tracking paradigm for great apes. We split the display of an individual in need versus an individual not in need into two conditions. In the ‘need’ condition (Figure 2A) an actor could not reach a toy due to a barrier, whereas in the ‘no need’ condition (Figure 2B) the actor was able to reach the toy. We are currently investigating the pupillary response of chimpanzees and bonobos, with a goal of testing all available apes from at least three facilities (of at least 30 individuals; ongoing data collection). We predict that great apes will show greater arousal when seeing an individual unable to reach a goal versus an individual that is able to reach a goal. This would indicate that great apes understand when other individuals are unable to reach goals on their own, and may be in need for help.
In summary, we provide data from an independent replication showing that infants’ understanding of others’ needs is a highly robust phenomenon that generalized across divers populations of human infants. We also test for evidence for the understanding of others needs in our closest living relatives, which would make a strong case that human prosocial understanding is not only rooted in early ontogeny but also in phylogeny.

Authors

• Moritz Köster, Freie Universität Berlin
  Presenting Author

• Christopher Krupenye
  Non-Presenting Author

• Tess Fulcher, University of Chicago
  Non-Presenting Author

• Amanda Woodward, University of Chicago
  Non-Presenting Author

• Zanna Clay, Durham University
  Non-Presenting Author