A recent study published in NeuroImage has shed light on the neural underpinnings of social bonds between sisters. The research found that when sisters watch a movie together, their brain activity is more similar than that of friends or acquaintances. This increased similarity was particularly evident in areas associated with complex cognitive functions, such as the default-mode network and sensory processing regions.
The study involved 30 healthy women aged 19 to 39, organized into 10 triplets consisting of two sisters and a female friend of one of the sisters. Each participant underwent four fMRI sessions while watching an edited version of the movie My Sister’s Keeper. The researchers found that the brain activity of sisters was more similar than that of friends, with similarities observed in widespread areas of the brain.
One of the most significant findings was the increased similarity in the default-mode network, which is involved in self-reflection and daydreaming. Sisters processed and evaluated the movie’s events in a similarly complex and reflective manner, suggesting that their relationship has a deep impact on how they perceive and understand the world.
The study suggests that homophily, or the tendency for individuals to form connections with others who are similar to them, may have a neural basis. The findings also highlight the importance of family ties and the unique bond between sisters, which can be characterized by shared experiences, upbringing, and emotional closeness.
Source: https://www.psypost.org/brains-in-sync-sisters-show-fascinating-neural-similarity-in-new-study/