By 4 months old, your baby will probably be able to hold his head steady when he's upright — but most babies' heads will still fall backward when their upper bodies are pulled up to a sitting position. Help your baby develop neck and head control by making a game of pulling him up to sit: With baby lying on his back (or perhaps your legs), grasp his hands and gently pull him up to sit — some funny faces and zooming noises will help him enjoy the ride.
More About Baby's Development
Baby Babble
How do I get my baby to sit up?
As soon as he holds his head up well, you can help encourage your baby to sit by propping him up in a seated position in an infant seat, a stroller or your lap. Sitting up with support in the stroller while you take a neighborhood walk is an especially good way to develop your baby's interest in sitting. As you walk, point out all the new things he can see from his upright position, from dogs and cars to passersby and other babies in strollers.
The more practice your baby gets sitting with help, the more likely he is to try sitting up on his own without a pillow or Mom's or Dad's hands to support him. As he's learning to sit, keep him on a blanket or activity mat to cushion any tumbles, and sit close by so that you can catch him if he topples over backward. To steady his wobbly sense of balance, roll a ball and play catch while you're both sitting, or hold his hands and sing a song, gently swaying to the rhythm.
Try placing a toy in front of your baby's feet too when he's sitting, and he may end up propping himself up on his hands as he plays with it. You can also place a toy near the top of his feet to get his attention. Then lift the toy up to his eye level: He'll reach for it while sitting up — and may even be able to stay seated on his own while he plays with the toy in his hands.
What not to worry about
As long as you give your baby plenty of opportunities to practice his sitting skills, he'll let you know when he's ready to sit up.
If your baby slumps over or slides off to one side even with support, he may not be ready to sit, and you can simply try again later. And babies who are new to sitting up may tire easily — he'll let you know when he's had enough by fussing, complaining or slumping.
If your little one doesn't sit with support by the end of month 5, it's not a cause for concern. Every baby develops differently and at his own pace. Some babies sit as early as 4 months, whereas others pick it up as late as 9 months. Just continue to offer plenty of chances to practice sitting with support, and lots of encouragement and distraction while your little one is upright (try putting his infant seat next to a mirror, or taking an extra spin around the block in the stroller), so that he gets to use and develop those upper body muscles.
але навряд чи він би отак з цими дітьми мирно позував перед камерою 
