Alexandra's immature frontal lobes are responsible for her suprising behavior.

Like most babies her age, 10-month-old Alexandra is supremely curious. So when researcher Adele Diamond of the Shriver Center - a leading laboratory investigating the minds of children - shows her a colorful toy, Alexandra watches intently. Diamond places the toy in one of two wells in the table between them, and after covering both wells with a cloth, asks Alexandra, "Where's the toy?" Immediately, the baby reaches for the correct well, and as a reward, she gets to play with her colorful prize. But minutes later, after watching Diamond hide the toy in the opposite well, Alexandra goes right back to search in the well where the toy was originally placed. Time after time, as Alan Alda looks on in amazement, Alexandra returns to the first hiding place to find her toy.

As an adult, Alan performs the experimental tasks accurately, but it takes him longer as they become more difficult.

Diamond believes that Alexandra is unable to override the initial connection and remember that the toy is now in a new hiding place because her brain, and specifically, her frontal lobes are still immature. In this segment, Alan watches Diamond and her colleagues conduct a variety of tests that reveal the tricky inner workings of a child's mind. In case after case, Diamond's brainteasers show how the undeveloped frontal lobes prevent children from making the correct choices that seem so obvious to adults. But when Diamond turns the tables and asks Alan to try a few of the tests himself, he has a hard time as well. In his case it's speed and not accuracy that's the problem.

For more on this topic, see the web feature:
Frontiers Profile: Adele Diamond