Intellectual can be described or explained as the ability of placing a high value on or pursues things of interest with intelligence and curiosity. This means that a person with this ability does not require no or minimal monitoring or supervision , because he/she knows what to do, where to look and how to go about it in achieving the desired or expected result.
These people are sometimes refer to as intellectuals.
In this case, Adams as described believed to possess the qualities of an intellectual person, and this make the minds of his parents to be at peace.