Children with Williams syndrome — a rare genetic disorder that leads to mental retardation and overt friendliness — hold stereotypes based on gender, but not race, according to a report published in Current Biology. Because those with Williams syndrome don’t have social fear, the study suggests racial stereotypes are based partly on fear.

Neuroscientists have discovered a population of cells in the smell-perception area of the rat brain that express the hormone vasopressin. The study, published in Nature, begins to unpack the complicated molecular interactions of the hormone in the brain, which could lead to new autism treatments.

Scientists have been unable to replicate work showing an association between oxytocin receptor genes and autism.

Many parents of children with autism show some mild traits of the disorder. Research on this group — labeled with the ‘broad autism phenotype’, or BAP — suggests that the genetic underpinnings that lead to language or social problems can manifest in very different ways.

A report in the October issue of Nature Neuroscience says the amygdala — the brain region that controls emotions, as well as the way individuals interpret and respond to social situations and recognize possible threats — governs the preference for personal space.

Genetic analysis of one Belgian family with a history of autism has pinpointed a piece of DNA on chromosome 16, within a segment thought to be missing in about one percent of all cases of autism. The unpublished data was presented on Saturday at the World Congress of Psychiatric Genetics in San Diego.

Studying the relatively well-defined genetics of Williams syndrome may help unravel the poorly understood genetic and neurobiological roots of autism, researchers say.

Applying an emerging technique that combines genetic data and brain scans, researchers have identified two new genes involved in schizophrenia. The method, called ‘imaging genetics’, holds promise for linking genes to brain function in complex psychiatric disorders, including autism.

The characteristic inability of a person with autism to respond to emotions may stem from sustained arousal in the amygdala, the brain region needed to interpret emotions from facial expressions.

A child’s language ability correlates with the volume of his or her amygdala ― the small, deep brain region that is strongly associated with emotion processing ― according to an unpublished five-year longitudinal study presented Wednesday afternoon at the Society for Neuroscience meeting.