People with a condition linked to autism typically do not like hugs, which could be due to delays at crucial points in the brain’s development in the womb. In a new study in mice with fragile X syndrome, wiring in the part of the brain that responds to touch was found to have formed late. This could also explain why people with this condition are extra-sensitive to physical contact, and highlights stages at which treatment could be most effective. Fragile X syndrome is caused by a mutant gene in the X chromosome, which interferes in the production of a protein called fragile X mental retardation protein. By recording electrical signals of mice that were bred with the condition, researchers found some connections in the brain matured late, suggesting there are windows for treatment that could be effective. Research into fragile X syndrome could help understand some aspects of autism.