An experimental group is the group in an experiment that receives the variable being tested. One variable is tested at a time. The experimental group is compared to a control group, which does not receive the test variable. In this way, experimental groups are used to find answers in an experiment.
1 At around 9 months of age, babies begin to pull themselves up to a standing position. 2  By 10 months of age, a baby should be able to grasp objects with thumb and forefinger.
The color red. As an infant, Samantha loved looking at the Coke cans I'd set out when guests were coming. It's no wonder: red is among the colors babies see best once their color vision first kicks in, at about 3 months. A newborn doesn't see in color at all, thus her early fascination with black-and-white patterns and playthings. Her color vision is fully in place by 4 months. Young children only really detect bold, primary colors; they probably discern reds and greens best, followed by blues and yellows, says Eliot.