Thank you for visiting our web page with illustrative videos of several of our studies! You will find short descriptions of our studies with links to the original research articles. We hope you find them useful — let us know if you have questions!
Please be aware that these videos are exclusively for educational and research purposes. They can only be used with explicit permission from the authors and reference to the respective articles. If you are interested in using them in lectures or talks, please email us at email@example.com.
Helping in infants and chimpanzees
What are the origins of altruistic helping? We found that 18-month-old infants already help in a variety of situations in which an adult is struggling to complete a task — without being asked to help or being rewarded for their efforts. In addition, we found that chimpanzees show some of these basic helping behaviors as well, highlighting the deep roots of altruistic behavior.
Child helps with an out-of-reach object
Child helps with an obstacle
Chimpanzee helps with a mould
Chimpanzee helps with a sponge
Child helps by correcting a wrong result
Child helps by correcting a wrong means
Chimpanzee helps with a dropped lid (v1)
Chimpanzee helps with a dropped lid (v2)
The origins of collaboration
In this study, we investigated whether children and chimpanzees are able to solve problems that require their collaboration with partners. In certain trials, the experimenter stopped participating in a joint activity, and we recorded whether children and chimpanzees would try to re-engage the partner to continue the collaboration or switch to individual problem solving instead. Both children and chimpanzees were able to coordinate with a partner, but only children tried to re-engage the partner during the interruptions.
Child: Parallel roles & re-engagement
Chimpanzee: Behavioral coordination
Child: Complementary roles & re-engagement
Chimpanzee: Coordination & no re-engagement
Do rewards help or hinder helping?
In this study, we were interested in the effect of rewards on children’s helping. We found that children who received a toy for helping during a treatment phase were later less likely to help during our test phase than children who had received praise or no reward at all. Material rewards can undermine children’s intrinsic motivation to help.
Treatment phase: No reward condition
Treatment phase: Praise condition
Treatment phase: Material reward condition.
Test phase: Child helps
Test phase: Child does not help
Helping in children and chimpanzees: The role of rewards and costs
These video clips show examples from three experiments with 18-month-old children and semi-free ranging chimpanzees. We found that both chimpanzees and human children helped altruistically, regardless of any expectation of reward (Experiment 1). They continued to help even when helping was made more effortful in that chimpanzees had to climb up into a raceway and children had to surmount an array of obstacles in order to help (Experiment 2). Furthermore, chimpanzees helped other conspecifics: When one individual was unsuccessfully trying to open a door which was blocked by a chain, the other individual helped by releasing the chain (Experiment 3).
Exp1: Child in condition Reaching/No Reward
Exp1: Chimpanzee in condition Reaching/No Reward
Exp3: Chimpanzee helps in experimental condition.
Exp2: Child in condition Reaching
Exp2: Chimpanzee in condition No Reaching
Do children share resources based on merit?
How do children share rewards after one person has worked more than the other? In this study, 3- and 5-year-old children played a fishing game with a puppet partner in which they both collected coins. Children either collected fewer or more coins than their partner. They could then divide sticker rewards between themselves and their partner. When children had collected more coins in the fishing game, they allocated more rewards to themselves than the partner. By contrast, when the partner had collected more, they divided up the rewards equally. These result shows that at 3 years of age, children already consider merit when sharing resources, but they do so in a biased manner as they value their own work contribution more than that of the partner.
Child and puppet partner play fishing game
Child gives more to self than partner
Experimenter explains sharing task
Child gives more to partner than self
Proactive helping in children
Will children help others who aren’t even aware that a problem has occurred? We found that starting at 2 years of age, children would help proactively without any prompts or requests from the person needing help. When an accident had occurred without the person even knowing, children would offer their help proactively.
Child helps by placing dropped can on the table
Child helps and comments on the situation
Child helps by handing dropped can to the experimenter
How children intervene against unfairness
Punishing others’ selfish behavior plays a key role in promoting cooperation. In our study, children could intervene against unfair sharing in ingroup and outgroup contexts. 6-year-olds showed ingroup favoritism when intervening against unfairness. However, 8-year-olds acted with less bias, indicating that ingroup favoritism influences human’s fairness behavior, but can be partially overcome with age.
Children’s fairness behaviors across the globe
We were interested to learn how children’s sense of fairness develops across cultural groups. All children happily accepted when resources were shared equally. When a peer received more than the self, already young children rejected such distributions (so-called disadvantageous inequity). However, around school-age, many children also rejected allocations that would result in more candy for the self than the peer (advantageous inequity aversion).
Child accepts an advantageous allocation
Child accepts a disadvantageous allocation
Child rejects an advantageous allocation
Child rejects a disadvantageous allocation
Children trade off costs and benefits for self and others
In this study, we investigated how children delay reward when there is a trade-off between waiting time and the size of the reward. We compared an individual context where the reward is for the child versus a context where the reward is for a peer.