Extrinsic rewards undermine altruistic tendencies in 20-month-olds.

@article{Warneken2008ExtrinsicRU,
  title={Extrinsic rewards undermine altruistic tendencies in 20-month-olds.},
  author={Felix Warneken and Michael Tomasello},
  journal={Developmental psychology},
  year={2008},
  volume={44 6},
  pages={
          1785-8
        }
}
The current study investigated the influence of rewards on very young children's helping behavior. After 20-month-old infants received a material reward during a treatment phase, they subsequently were less likely to engage in further helping during a test phase as compared with infants who had previously received social praise or no reward at all. This so-called overjustification effect suggests that even the earliest helping behaviors of young children are intrinsically motivated and that… 

Figures from this paper

Extrinsic Rewards Diminish Costly Sharing in 3-Year-Olds.
TLDR
In all scenarios, children's willingness to engage in costly sharing was negatively influenced when they had received a reward for equal sharing during treatment than when theyHad received praise or no reward.
Plasticity of altruistic behavior in children
The present study investigates the plasticity of altruistic behavior in children, analyzing the effect of a short intervention on 6- to 7-year-olds. After a 10-session intervention performed in a
A New Look at Children’s Prosocial Motivation
Young children routinely behave prosocially, but what is their motivation for doing so? Here, we review three studies which show that young children (1) are intrinsically motivated rather than
The roots of human altruism.
TLDR
The results suggest that human infants are naturally altruistic, and as ontogeny proceeds and they must deal more independently with a wider range of social contexts, socialization and feedback from social interactions with others become important mediators of these initial altruistic tendencies.
Giving Leads to Happiness in Young Children
TLDR
By documenting the emotionally rewarding properties of costly prosocial behavior among toddlers, this research provides initial support for the claim that experiencing positive emotions when giving to others is a proximate mechanism for human cooperation.
Toddlers' prosocial behavior: from instrumental to empathic to altruistic helping.
TLDR
Findings suggest that over the 2nd year of life, prosocial behavior develops from relying on action understanding and explicit communications to understanding others' emotions from subtle cues.
The impact of choice on young children's prosocial motivation.
Giving Preschoolers Choice Increases Sharing Behavior
TLDR
It is proposed that the experience of choice is critically tied to the expression of young children’s altruistic behavior, and it is suggested that children rationally infer their prosociality through the process of making difficult, autonomous choices.
...
...

References

SHOWING 1-10 OF 21 REFERENCES
Helping and Cooperation at 14 Months of Age.
  • F. Warneken, M. Tomasello
  • Psychology
    Infancy : the official journal of the International Society on Infant Studies
  • 2007
TLDR
Two experiments investigated the proclivity of 14-month-old infants to altruistically help others toward individual goals, and to cooperate toward a shared goal, which is integrated into a model of cooperative activities as they develop over the 2nd year of life.
Consequences of superfluous social constraints: Effects on young children's social inferences and subsequent intrinsic interest.
ion and generalization should also characterize the manner in which children acquire an understanding of the relationship between the receipt of performance-coritingent rewards and one's competence
Undermining children's intrinsic interest with extrinsic reward: A test of the "overjustification" hypothesis.
A field experiment was conducted with children to test the "overjustification" hypothesis suggested by self-percepti on theory—the proposition that a person's intrinsic interest in an activity may be
Altruistic Helping in Human Infants and Young Chimpanzees
TLDR
It is shown that human children as young as 18 months of age quite readily help others to achieve their goals in a variety of different situations, which requires both an understanding of others' goals and an altruistic motivation to help.
Effects of Reward Contexts on Young Children's Task Interest
Abstract Two studies designed to examine the consequences of rewards and the contexts in which they are used on children's task interest are presented. In Experiment 1, 56 preschoolers in three
Attribution of Dispositional States by 12-Month-Olds
TLDR
Three experiments are reported suggesting that 12-month-old infants not only can recognize goal-related action, but also can interpret future actions of an actor on the basis of previously witnessed behavior in another context.
Effects of Externally Mediated Rewards on Intrinsic Motivation.
Two laboratory experiments and one field experiment were conducted to investigate the effects of external rewards on intrinsic motivation to perform an activity. In each experiment, subjects were
Spontaneous Altruism by Chimpanzees and Young Children
TLDR
Experimental evidence that chimpanzees perform basic forms of helping in the absence of rewards spontaneously and repeatedly toward humans and conspecifics is reported, indicating that chimpanzees share crucial aspects of altruism with humans and suggesting that the roots of human altruism may go deeper than previous experimental evidence suggested.
The Social Psychology of Prosocial Behavior
Contents: Preface. An Introduction to Prosocial Behavior. The Origins of Prosocial Behavior: Are People Selfish or Selfless by Nature? The Context: When Will People Help? Why Do People Help? Planned
A meta-analytic review of experiments examining the effects of extrinsic rewards on intrinsic motivation.
TLDR
A meta-analysis of 128 studies examined the effects of extrinsic rewards on intrinsic motivation, finding that Tangible rewards tended to be more detrimental for children than college students, and verbal rewards tend to be less enhancing for children compared with college students.
...
...