Psychology v/s Logic

Suppose the given data is - David is teaching vectors to Bryan. And they are in the same class (same age). One commonsense inference - So David is better at vectors than Bryan. The question is - why does a particular inference strike us with more likelihood when we come across a piece of data? Here, there are other inferences like - 1) So Bryan is learning. 2) So Bryan knows (would know) what a vector is. 3) Davis seems to be a helpful student. etc. to name a few. The machine and humans would know the piece of commonsense fact that ‘Teachers are generally older than their students’. This would contradict line no.2 of the given data. And in the LIGHT OF THIS CONTRADICTION, this very inference should be inspired - i.e. So David is better at vectors than Bryan. (They would now be compared in their abilities since they are now known to be fellow-students). This wouldn't have been the primary inference if it wasn't given in the data that they are of the same age. This implies there is a motivational fluid of impending conclusions running through, while the mind is doing commonsense reasoning. That is why some inferences get a preference over the others i.e. humans are more likely to jump to them than others. Logic cannot distinguish between these (unless of course these internal motivational rules themselves are somehow fed in as additional logic-statements into the machine).