People with Williams syndrome are often affable and hyperverbal, demonstrating the decreased inhibition ability that stems from dorsal-frontal deficits. Some studies suggest that the amygdala of a person with Williams syndrome has greater volume than the average person's (though it is smaller than average in childhood). In general, neuroimaging studies demonstrate that individuals with Williams syndrome have diminished amygdala reactivity in response to socially frightening stimuli (such as disapproving faces), but demonstrate hyperreactivity in the amygdala when presented with nonsocial fear stimuli (such as frightening animals). This may partially account for the apparent absence of social inhibition observed in individuals with the syndrome, as well as the prevalence of anxious symptoms (but see fear for details on the relationship between the amygdala and fear response). There is also evidence that individuals with Williams exhibit hyper amygdala activity when viewing happy facial expressions.