I once witnessed a minutes-old baby grab her mother's shirt so tightly that two nurses could not pry her away to weigh and measure her. They decided to try again later, when she let go of her own accord.
The grasp reflex is one of many reflexes a baby is born with. Lay your finger on the palm of a baby's hand, and she will usually clamp her tiny — yet mighty — fingers around it. In fact, a newborn's grip is so strong that she can briefly support her own weight. Scientists hypothesize that human babies inherited this reflex from primates; the instinct to cling tightly has obvious survival benefits.
A recent study also showed that when they hold on to their mothers, infants' heartbeats slow, suggesting that babies derive a calming sense of security from contact with Mom.
As babies grow, they replace the involuntary grasping reflex with a keen interest in trying to control their movements, negotiating such fascinating activities as spoon holding and sippy-cup-against-the-high-chair whacking. At this point, they move on to dropping, throwing, and letting go of everything in sight. Except, that is, when a coveted toy might be taken away, in which case they rediscover their iron grip. Whoever said taking candy from a baby is easy has obviously never tried.
Adapted with permission from "Why Babies Do That: Baffling Baby Behavior Explained," by Jennifer Margulis, published by Willow Creek Press. 2005 by Jennifer Margulis. All rights reserved.