What is the name of the effect or concept behind getting along better with people after time apart? I notice this happens ubiquitously. When siblings are apart in college, or kids away from parents due to college, or even long distance relationships - during a reunion (like over the holidays) only the positives tend to be highlighted, there is generally less fighting and more harmony and the overall relationship feels much better than it would be on average if the separation was not there.

What is the name of this effect, if it has one? Or are there any results/studies about this?
In general, I would have said the opposite: there's a robust literature on familiarity driving liking, even with non-social stimuli like shapes:


  https://en.wikipedia.org/wiki/Mere-exposure_effect


This is also true with people. There may be some kind of an effect whereby people who are familiar and then separated bicker less after the break than before, but I haven't seen this studied. I'd suggest you look at terms like conflict in close relationships for psychological research, e.g.:


  Simpson, J. A., Rholes, W. S., &amp; Phillips, D. (1996). Conflict in close relationships: An attachment perspective. Journal of Personality and Social Psychology, 71(5), 899-914.
  http://dx.doi.org/10.1037/0022-3514.71.5.899