[DavidG]

1.2.2 Maintenance Aptitude
Unlike other characteristics Maintenance aptitude gives a benifit differnt that what appears at first. Increasing Maintenacne Aptitude from 100% to 110% give significantly more than a 10% advantage from normal. This will in fact decrease the base maintance paid on ships from the default of 25% of it's cost by 10% to 15%.

(PS there are a few other characteristics that I'm told work in a similar fashion. like happiness, reporduction and resistance but I'm not sure what they are)