Various kinds of stress produce cortisol in the brain, which has all sorts of bad effects there. For example, fetuses who are washed in mom's cortisol become babies with impaired cognitive development. But it turns out sensitive care by mom during infancy and toddlerhood can make it better. Presumably this kind of care affects the hormones the kid's brain secretes, just as stress does, only for the better.
At the same time, mom's sensitivity in talking with a kid developing autism is related to the kid's language growth. Parenting styles don't cause autism, but they might help ameliorate it. Or not.
Cool. Moms fix everything. Or is that oxytocin?