The team of three psychologists at the University of British Columbia in Vancouver, Canada, gave toddlers some treats and a few minutes later asked the toddlers to give one of their treats to a puppet. The children were also given an extra treat and asked to give this to the puppet too.
The toddlers' reactions to these requests were videotaped and then rated for happiness. The researchers concluded that the toddlers showed greater happiness when they shared their own treat than when they shared the extra treat. This suggests that this behavior is emotionally rewarding for the children.
"People tend to assume that toddlers are naturally selfish," study lead author Lara Aknin said in a university news release. "These findings show that children are actually happier giving than receiving."