Self-injurious and aggressive behaviors are highly prevalent and persistent among males with fragile X syndrome (FXS), a genetic cause of autism spectrum disorder (ASD). These behaviors, such as hand-biting and hitting others, affect a significant portion of males with FXS. However, little is known about the persistence of these behaviors and the associated risk factors. To address this, researchers conducted a longitudinal study involving 79 males with FXS over an eight-year period. The study found that self-injurious and aggressive behaviors remained persistent throughout the participants’ lives. Specifically, 34.2% of participants displayed persistent self-injurious behavior, while 21.5% showed persistent aggressive behavior. The study also identified risk markers for these behaviors, such as repetitive behavior and impulsivity. These findings highlight the need for early intervention strategies to reduce self-injury and aggression in individuals with FXS. This study is the first to document the long-term persistence of these behaviors in FXS. The author of the article, Joana Carvalho, has a background in biology and biomedical sciences. She conducted part of her studies in France as a recipient of two Erasmus scholarships.