Justice Rooted in the Mind

Illustration of the experiment After watching animations depicting aggressive interactions in which third-party agents did or did not intervene, the infants are presented a couple actual cubes with colors and features corresponding to characters appearing in the animation to measure on which characters the babies chose. © 2017 Kazuo Hiraki.

University of Tokyo researchers have demonstrated that babies not yet able to speak affirm protective behavior defending the weak from the strong, suggesting that such tendencies are inherent in humans.

Whether an infant understands and affirms third-party interventions protecting victims from aggressors is considered a fundamental human characteristic involving morality, justice, and highly social behavior benefiting society. Interventions by a third party to protect those under attack are generally admired and associated with our notions of morality, justice, and heroism. We begin to engage in this type of intervention by preschool age, but exactly when we start to affirm such interventions performed by others has been hard to pin down.

The research group led by Professor Kazuo Hiraki at the University of Tokyo’s Graduate School of Arts and Sciences used animations to study these developmental origins in a group of 132 infants aged 6 months and 10 months. After watching an animation in which a third-party agent intervened during an aggressive act and another in which it did not get involved, the 6-month-old infants preferred the one in which there was interference. The babies also appeared to understand that the interfering agent was protecting the victim from the aggressor. However, only the 10-month-olds understood the intentions of the interfering agent in assessing the intervention.

The current findings are significant in that they shed light on the developmental trajectory of when infants become cognizant and begin to affirm protective interventions by third parties.

Determining how and when children incorporate abilities of affirming protective interventions on behalf of the weak into their developing notions of morality, justice, and heroism is the ultimate aim of this research.

“We were surprised when we saw the results indicating that even at 6 months infants can understand the relationship between aggressor, victim, and third-party intervenor,” says Hiraki. He continues, “Considering 6-month-old infants still lack social experience points to the possibility that humans are predisposed in affirming such protective interventions of defending the weak, and that this trait plays a major role in guiding our sense of justice.”