Tendency to overestimate the numbers of enemy in air combat?

[GuerraCivil]

Looking from various records of both sides of the Spanish Civil War and Sino-Japanese war it seems that pilots of both sides regularly claimed that the enemy had a clear numerical superiority. Also looking the combat reports of some other air war conflicts it appears that pilots had a strong tendency to claim that the enemy was numerically superior in combat as it really was.

Big air battles with lots of planes swirling around must have been confusing and it must have been difficult to tell if the enemy formation was actually composed of 20, 30 or 40 planes - 10-15 wildly manouvering enemy planes in a series of dogfights may well have looked like 30 or 40...

However sometimes I get a feel that some pilots routinely reported of numerically superior enemy which was defeated despite the odds. That they never defeated numerically inferior or equal numbers but fought always against superior numbers. Comparing the surviving enemy records it is apparent that they have very often seen more enemy planes at the sky than there actually was.

Could it be that there was a "glorifying" factor playing a part in the combat reports? That it was somewhat more glorious to claim to have defeated numerically superior enemy than one with equal or inferior numbers? Not that it was a conscious but rather a inconscious way to see things. It is very human for us to remember or tell something in the way that it is more flattering for ourselves. That is not necessarily or twisting things against our better knowledge as we may actually believe that the more flattering or more "glorious" version of events (for us) is the "confirmed" truth.

The overestimating the numbers of the enemy involved in combat has been so regular phenomenon that it should be studied and explained - maybe it was just a confusion but why the confusion led so often to the overestimation of the enemy numbers? Is the overestimation of the number of enemy planes in combat somewhat similar phenomenon to the overclaiming?