Research into the structure of the brain indicates that social interaction is a key component in building a healthy brain, while loneliness can have a negative impact on neurological development.
Reduced social interaction may be associated with lessened growth in key areas of the brain, such as the prefrontal cortex, which is the area of the brain responsible for decision making, the hippocampus, an area of the brain closely associated with memory and learning, and the amygdala, which is responsible for processing emotions.
Indeed, some research has suggested that the more social a person is, the larger their amygdala is likely to be.