“…In other studies, social interaction was recorded using children's verbal, gestural, or physical interaction with others, such as vocalizations toward others, social gestures, sharing, and physical contacts (Beckman & Kohl, 1984;Chandler, Fowler, & Lubeck, 1992;Dunn, 1991;Guralnick, 1981;Guralnick & Groom, 1987a, 1988Kallam & Rettig, 1991;Martin et al, 1991;Rettig et al, 1993).…”