Since subthreshold autistic social impairments aggregate in family members, and since attentional dysfunctions appear to be one of the earliest cognitive markers of children with autism, we investigated in the general population the relationship between infants' attentional functioning and the autistic traits measured in their parents. Orienting and alerting attention systems were measured in 8-month-old infants using a spatial cueing paradigm. Results showed that only paternal autistic traits were linked to their children's: (1) attentional disengagement; (2) rapid attentional orienting and (3) alerting. Our findings suggest that an early dysfunction of orienting and alerting systems might alter the developmental trajectory of future ability in social cognition and communication.