What is induction exactly in human brain?

It is going from plenty to particulars to the general. It is very handy as general takes much less room in ones memory than collection of particulars. Effect of such compression is the reduction in the degree of detected randomness.
Source- Nassim Nicholas Taleb
This is the reason why people very easily generalise things they are discussing or debating without understanding every case on the topic because we can not remember many cases in your brain but this is excuse not the solution. Solution will be to acknowledge that your conclusion or theories have limitations and works in few specific cases and is not tested on other cases so don't know the result from those unknown inputs.