The growth differences vary between autistic boys and girls and are most apparent among children with prominent social difficulties.

In this edition of Null and Noteworthy, a large clinical trial goes sideways, while memory and emotions hold up.

Many autistic people have a little-known trait called alexithymia, defined as having difficulty identifying one’s own emotions. New research suggests that the overlap has been confounding studies of emotional issues in people with autism for decades.

Treating cognitive inflexibility — for example, by practicing problem-solving — might help ease anxiety and depression in autistic people.

How autistic people look at a face may be linked more to alexithymia, a condition marked by difficulties recognizing one’s own emotions, than to autism.

Researchers are studying how the intense passions of autistic people shape the brain, improve well-being and enhance learning.

Autistic children who have difficulty managing their emotions are also likely to take medication and need assistance from emergency responders.

Autistic people who have trouble identifying their emotions are also likely to have anxiety, depression and problems with social communication.

Girls with autism tend to start puberty earlier than their peers do, which may intensify their social difficulties and put them at an increased risk for bullying and mental health conditions such as depression.

Conversations between an autistic and a typical person involve less smiling and more mismatched facial expressions than do interactions between two typical people.