Your little hero develops the skill to properly recognize faces when he surpasses this stage of life. Your little baby might be familiar with you and your partner, which is indeed a positive development milestone. Make it a habit to greet your baby with a smile every time you meet him during the day. This would encourage him to respond in the same manner.
What you need to know
Social development in growing infants is quite important. You as parents, should help your baby meet other members in the family so that he gets to recognize most of them. It would take time for your baby to settle down among a large group of people. Do not panic and make sure your baby is part of all family picnics and get-togethers. Once your baby starts feeling easy, he would start greeting everyone with a big chuckle.