By age 2, children with autism show difficulty with movement, communication, emotional control and problem-solving, distinct from the symptoms of children with other disorders, reports a study published in February.

Among the younger siblings of children with autism who do not have the disorder themselves, more than one-quarter show developmental delays at their first birthday, according to a study published in April.

Do genetic differences or diagnostic biases account for the gender imbalance in autism? Catherine Lord, David Skuse and Angelica Ronald weigh in.

Children living in low-income neighborhoods with high unemployment rates are more likely to be diagnosed with autism than are children who live in high-income communities, reports a large Swedish study published 26 February in the Journal of Psychiatric Research.

Children who show several repetitive behaviors — such as flapping their hands or spinning their toys — at their first birthday have nearly four times the risk of autism of children who don’t show repetitive behaviors. That’s the conclusion from a study published in the March issue of the Journal of Child Psychiatry and Psychology.

Evidence is finally accumulating that early diagnosis and behavioral interventions improve the lives of people with autism. Even so, increasingly the question isn’t just whether early intervention works but also the best age at which to intervene.

Babies later diagnosed with autism tend to stare at objects after picking them up at much later ages than controls do, according to a study published in Behavioral Brain Research.

Infants later diagnosed with autism are slower to learn how to sit and stand and are less likely to spontaneously change positions than their typically developing peers, reports a study published 18 September in Infancy.

Baby boys later diagnosed with autism lose interest in other people’s eyes between 2 and 6 months of age, according to a study published today in Nature. This is the earliest behavioral marker of autism found to date.

Watch the complete replay of Lonnie Zwaigenbaum discussing what studying siblings of individuals with autism can tell us about risk and early detection of the disorder. Submit follow-up questions.