Ad Hominem ("to the man"): a person's character is attacked instead of his argument? EX:

An example of an Ad Hominem attack would consist in attacking the person because of an aspect of his personality, ethnic origin, race, or professional background, instead of attacking the argument.

For example, suppose an engineer and a medical doctor are discussing about some aspect of the human body. If the medical doctor dismisses the engineer's argument simply because his profession is not part of the medical sciences, and without considering the validity or not of the engineer's argument, then, the doctor is commiting an Ad Hominen attack.

answer; ///any two strangers are likely to share many coincidental similarities;