Social and cardiac responses of young children with autism.

Sigman et al. (2003) watched preschoolers with autism while they viewed short videos. Half the clips showed people talking and playing. The other half showed objects moving without people.

The team tracked how long each child looked at the screen. They also taped a small heart monitor to each child’s chest. The goal was to test the old idea that autistic kids avoid people because people make them feel too excited or nervous.

The autistic children looked at social videos just as much as non-social videos. Their eyes did not avoid people.

Instead of speeding up, their heart rates slowed down when people appeared. This calm heartbeat goes against the “hyper-arousal” story. Social inattention is not simply a flight from stress.

Pan et al. (2025) and Polzer et al. (2022) later saw the same flat heart-rate pattern. They added eye-tracking and EEG and confirmed that autistic preschoolers show low physiological spark during social scenes.

Kaartinen et al. (2012) seems to disagree: they found bigger skin-conductance spikes when autistic kids met direct eye contact. The difference is age and demand. Preschoolers watching relaxed videos stay calm, while older kids facing a staring adult can feel stress.

Neuhaus et al. (2016) showed context matters. Heart-rate rose only when autistic boys talked with a familiar adult, not with a stranger. Together these studies replace the single “over-arousal” rule with a simpler idea: social settings can excite or calm, depending on age, partner, and task.

Stop assuming kids look away because they are overwhelmed. If a child’s heart is slowing, he may be under-aroused, not escaping. Try brief, animated social openings instead of calm faces. Pair people with the child’s favorite sights or sounds to add the missing spark. Track eye gaze and heart-rate in your assessments; flat lines can guide you to boost stimulation rather than reduce it.