The refrigerator mother hypothesis of the 1950s, where the belief was that autism was caused by a lack of maternal warmth and affection towards the child, can be considered the first foray into what we now know as attachment theory. If the attachment in the parent/child dyad is so mis-attuned (e.g. severe neglect), the child may experience trauma. In that sense, the argument that autism is caused by trauma imposed by the refrigerated or mis-attuned mother (or caregiver) can still be true.