It is very common for younger siblings to imitate an older brother or sister, especially when they spend a lot of time together. If your younger child is copying your autistic daughter’s stimming behaviors, it does not necessarily mean he has autism. Young children naturally learn by watching and imitating those around them.
Instead of focusing on stopping the stimming, try increasing opportunities for your younger child to engage in different activities and interact with other children and adults. Spend one-on-one time with each child every day, encourage play that keeps their hands and minds busy, and praise your younger child when he chooses appropriate play or engages in positive behaviors. If the siblings begin stimming together for long periods, gently redirect them to a fun activity, outdoor play, music, a game, or another shared interest rather than simply telling them to stop.
Most importantly, avoid drawing too much attention to the stimming itself. The goal is to teach alternative, engaging activities while allowing each child to express themselves appropriately. If you notice that your younger child’s imitation begins to interfere with his learning, communication, social interactions, or daily activities, discuss your concerns with your pediatrician or a developmental specialist. With guidance and consistent encouragement, many children naturally develop their own interests and behaviors over time.