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.
You should know that many babies are born with blue eyes, which may change color (usually becoming darker) over the course of the first year of life. Usually your baby's eye color at 6 to 9 months should be close to the permanent hue.