From the University of Cambridge, this latest study involving adults with Asperger Syndrome are more sensitive to distraction by faces than IQ-matched controls. For everybody (and children more than adults), photographs of angry faces on an attention task like the Stroop are distracting. But at least in this study, those in the AS group had more trouble attending to the Stroop task whether the emotional expressions were angry or emotional.
There is a lot of common misunderstanding about eye contact - culturally many people interpret poor eye contact as negative, unfriendly, insincere, rude, or just strange behavior. It's paradoxical in a way because although not showing eye contact is interpreted as being insensitive - in many cases the problem is too much sensitivity to the presence of a face (looking directly at someone hijacks the brain's attention resources).
We've seen professionals mistake poor eye contact as a sign of an autism spectrum disorder. But decreased eye contact occurs in many situations such as of course shyness or social anxiety, but also any situation that limits attention or other memory resources. Researchers who study gaze aversion have found that most people will need to look away when performing difficult cognitive tasks of any sort - probably because it might help divert visual memory or attention resources to the job (in fact, check out the Gaze Aversion link below if you want to find references about how looking away improves cognitive performance!).
Most parents are embarrassed when their children don't look up when they are being introduced to others - but usually just a little bit of leeway is what's needed. Often children need some time adjust to a new environment (even the chair for AS subjects interfered with Stroop attention) and we need to remember to give them that time.
Stroop Distraction for All Faces in Aspergers
Eide Neurolearning Blog: Eye Contact in Autism
Eide Neurolearning Blog: What Our Eyes Say - Social Anxiety and Math Problem Solving
Gaze Aversion Research