Children who have an older sibling with autism have a higher risk of developing the disorder themselves than those who have no siblings with the disorder. This fact can leave the parents of those at risk on the lookout for symptoms. But how well do parental concerns match up with a child’s actual behavior? Not so well, according to a study published 24 February in the Journal of Autism and Developmental Disorders. Researchers asked more than 3,000 mothers to keep diaries chronicling their infants’ first year of life. Although mothers of high-risk ‘baby sibs’ were more likely to pen concerns about language, social skills and repetitive behaviors than were mothers of babies at average risk, their reports overstated their children’s behavior problems during infancy.

People have bigger brains than chimpanzees do, and a new study in mice hints at why. The study, published 19 February in Current Biology, finds that embryonic mice carrying the human version of a gene called HARE5 develop brains that are 12 percent larger than those of mice with the chimp version of the gene. The findings suggest that evolutionary changes in the sequence and activity of HARE5, which lead to a greater proliferation of neurons-to-be, helped to set our brains apart from those of our closest living relative. Perhaps it’s part of what made our brains so complex and prone to disorders such as autism.

Researchers were once hopeful that drugs targeting mGluR5, a receptor for the neurotransmitter glutamate, would ease symptoms of fragile X syndrome. But after a string of failed clinical trials, they’re looking for more sensitive ways to assess how well the drugs work. “We have to spend more time doing the boring things, the least rewarding work, which is to prepare the field for the trials by developing more outcome measures,”Walter Kaufmann, a neurologist at Boston Children’s Hospital who worked on one of the trials, said in an article published 27 February in Nature Reviews Drug Discovery. Elizabeth Berry-Kravis, who also worked on one of the trials, advocates a measure based on learning and thinking.

You probably saw the debate about ‘the dress’ last week. You know, the one that’s white and gold, or blue and black, depending on who’s looking at it? People with autism say the disagreement offers a glimpse of how they experience the world. “[It’s] a really good way of acknowledging that people see things differently, perceive things differently, and one way is not necessarily superior to the other,” Ari Ne’eman, president of the Autistic Self Advocacy Network, told BuzzFeed News in an article published 27 February.