Both should be part of school but like DiaperDiva says you have to make tough choices. After reading "Emotional Intelligence" I have begun to feel that social skills are more important as they have to do with relationships with friends, spouses, and children - major factors in life. As the book hints that though you might know tons of stuff, if you cannot interact well with others then what you know may be of little benefit to yourself or others. Letting school socialize your children, however, is like teaching then to swim by throwing them in the river. Peers have some effect, lots say some.
I think our culture tends to reduce parenting to job preparation with academics, for most, having to do with college and then a job. On the other hand, the more you know, the more you have in common with others and the more you have to share and exchange with them so thus, I feel, academics also has to do with being social. People like it if you know something of their line of work or interest or country they're from. Just having read the same book as as others makes you a part of a community.
"Parents are usually more careful to bestow knowledge on their children rather than virtue, the art of speaking well rather than doing well; but their manners should be of the greatest concern."
~ Richard Buckminster Fuller