Click the citizen tab, which is the button of an image of a person. Then click one of the flags appearing next to each of the citizens’ names. It’ll give a basic run down if the stats, then you can click attributes (third tab on the bottom of the character sheet) which gives more info.
The three main stats, mind body and spirit, determine different aspects of your hearthlings. Hearthlings who craft (carpenters, masons, and blacksmiths) will work best with a high (5 or 6) Mind for the crafting, and a mid (4 or ) Body for making fine materials. Hearthlings who work (farmers, trappers, and workers) do well with a high Body and low (1 or 2) Spirit so they work well and will run from danger. Hearthlings who fight (footmen) do well with high Body and high Spirit so they can fight well and aren’t probe to run unless ordered to.