A review of psychology and neuroscience suggest that when growing child reaches 18 years they experience major changes in developments of understanding, emotional maturity, hormonal development, and others which specifically related to the brain activity.
There are three stages of adolescence - early adolescence from 12-14 years, middle adolescence from 15-17 years and late adolescence from 18 years and above. Is 25 age, new cut-off point for adulthood? Need to be tested more.
May be an error. Given that our learning is "hardwired" in the brain, and acquisition of new knowledge / new skills only slows down, but doesn't come to an halt, this means that development should slow down, but not cease.