Infants aged 1 who sweat less when they are scared may become more aggressive at age 3, according to new research.
Lower levels of sweat, as measured by skin conductance activity (SCA), have been linked with conduct disorder and aggressive behavior in children and adolescents.
Researchers hypothesize that aggressive children may not experience as strong of an emotional response to fearful situations as their less aggressive peers do; because they have a weaker fear response, they are more likely to engage in antisocial behavior.
Psychological scientist Stephanie van Goozen of Cardiff University and colleagues wanted to know whether the link between low SCA and aggressive behaviors could be observed even as early as infancy.
To investigate this, the researchers attached recording electrodes to infants’ feet at age 1 and measured their skin conductance at rest, in response to loud noises, and after encountering a scary remote-controlled robot. They also collected data on their aggressive behaviors at age 3, as rated by the infants’ mothers.
The results revealed that 1 year-old infants with lower SCA at rest and during the robot encounter were more physically and verbally aggressive at age 3.
The study has been published in Psychological Science.