Is it autism or not?

Rocking back and forth, flapping hands and fixating obsessively on one thing — these can be cute and typical behaviors for a 6-month-old baby but are concerning after a certain age. Scientists have identified these signs as reliable red flags when it comes to identifying autism in young children. Among children who go on to be diagnosed as autistic, these repetitive behaviors may even increase around age 1.

The study needs more fine-tuning to point to these behaviors as a clear sign of autism, but researchers say it’s a promising start. The earlier autism is diagnosed and the earlier therapy begins, the better a child will adapt to life long-term.

Another study from the Boston Children’s Hospital showed that electroencephalograms, or E-E-Gs, which measure brain activity, could identify kids with high and average risk of autism.

Other signs of autism include aversion to making eye contact, difficulty developing nonverbal communication skills, such as facial expressions and mannerisms, and trouble making friends with kids their own age. Inability to or a delay in speech is also a major sign — up to 40 percent of kids with autism don’t speak. They might also have trouble starting and keeping up a conversation. Instead, they will often repeat a phrase they’ve heard before.

Kids with autism could display a peculiar interest in a part of a toy, like a wheel, rather than the whole. They might also fixate on a certain interest, such as space or video games. They crave routine, like riding in the same car seat every day.

Experts aren’t sure of the cause of autism, but it likely has some genetic links. If a child has autism, his or her siblings have a 20 percent chance of getting it as well.

In any case, early diagnosis and therapy is the best bet for a child with autism to develop to their fullest potential.