Heterosis, also known as hybrid vigor

From 'Optimal Mating Distance' Really Does Lead to Super Fit Offspring by Jim Erickson-Michigan.

The genetic distance between the two parents of an individual, known as mating distance, influences the individual’s fitness via two competing mechanisms.

On one hand, increasing the genetic distance is beneficial because of the phenomenon of heterosis, also known as hybrid vigor. Plant and animal breeders routinely exploit the genetic benefits of this phenomenon by breeding together two distinct parental lines.

Such crosses can impart increased fitness by producing hybrid offspring that are larger and healthier—and in the case of corn plants, more productive—than their inbred parents.

But too large a genetic distance between individuals can be harmful owing to genetic incompatibility.

Biologists have long suspected that the optimal mating distance represents an intermediate point that marks a tradeoff between the advantages of heterosis and the harmful effects of genetic incompatibility. The new study confirms those suspicions.

The results suggest that in both plant breeding and conservation, using mating distances close to the OMD, the optimal mating distance, will likely optimize a suite of fitness-related traits.

In epistemology there is a similar function to heterosis, though I do not know if it has a name.

We know that some of the richest cultural moments come when two competent cultures interact with one another, the knowledge, ideas and assumptions of one serving as a catalyst to the other leading to new knowledge, art forms, ideas and creativity. Think of Hellenism in the Middle East, Calvinist Scotland interacting with Mercantilist England, and the multiple cultural strands in pre-revolutionary America yielding such a unique synthesis - a nation forged in ideas rather than blood and land.

But, there is always a but . . . There has to be some optimal epistemic overlap, the parallel to the optimal mating distance. If the epistemic Venn diagram of two cultures is nearly identical, the hybrid vigor effect is weak. If the epistemic Venn diagram of to cultures has no overlap, then you are much more likely to have catastrophic conflict rather than constructive vigor.

But what is the optimal cultural epistemic overlap? Who knows. We are just beginning to reach understanding of this real phenomenon in biology. And we are likely still a long way from it being settled.

Measuring cultures, values and epistemology is still nascent and therefore we are likely decades or longer from material progress.

Interestingly, where cultural epistemic overlap, in one form or another, has probably been explored the most is in sciece fiction where the challenges of mutual comprehension is almost a trope.

As an example of a very light version of this exploration of cultural epistemic gap, think of The Midwich Cuckoos by John Wyndham. A small population of alien hybrid children are spawned on Earth. They physically resemble humans but have a shared telepathic capability.

As they grow up, it becomes increasingly apparent that they are, at least in some respects, not human. They possess telepathic abilities, and can control others' actions. The Children (they are referred to with a capital C) have two distinct group minds: one for the boys and another for the girls. Their physical development is accelerated compared with that of humans; upon reaching the age of nine, they appear to be sixteen-year-olds.

The Children protect themselves as much as possible using a form of mind control. One young man who accidentally hits a Child in the hip while driving a car is made to drive into a wall and kill himself. A bull which chased the Children is forced into a pond to drown.

Lewis explores, though only as a subsidiary theme, the question about the consequences of such cultural epistemic distance. When there is some form of a functioning group mind, who has the burden of guilt for a crime? Is it just the child struck by the car? The children in immediate proximity? The entirety of the group mind?

Robert Heinlein's Stranger in a Strange Land is probably the better known in this genre of intercultural epistemic mixing.