At around six months, your baby acquires fine motor skills, which leads to the milestone of learning to manipulate fingers. Babies go from grasping with a whole hand to holding small things between thumb and forefinger. With the development of this skill, babies learn to explore in depth, having surpassed the simpler skill of grabbing or swiping. Activity centers with dials to spin and buttons to push are ideal for this learning stage.

Next up: how to uncurl fingers. Baby discovers that the way to let go of an object is by uncurling fingers and will practice this new skill constantly. The 'drop it' game will tire you long before baby moves on to something new. The 'game,' or skill, will be a source of pride each time something is held and then jettisoned. At the same time, baby discovers: 'When I drop something, it always falls down—never up.' Your budding physicist has learned the concept of gravity!