Hybridization is the term used when long exposure to the Dungeon causes changes to personnel.
The mechanism causing hybridization is unknown. Over the decades however most delving governments have learned how to deal with and prevent it. Long term exposure, without trips to the surface is the only known cause.
Hybrids develop changes in both their physical and mental states. In some cases it is a mild, though detectable boost in physical abilities. In extreme cases gross morphological changes and psychosis is the result.
The American NATIVE SONS program utilizes these hybrids as trackers and guides. Teams accompanied by them showed dramatically higher success and lower mortality rates.
Like xenofauna, hybrids can not survive without Dungeon exposure. However the exposure need only be intermittent instead of constant. The hybrids are stuck between upstairs and downstairs. If they spend too much time in either world, they'll start to degenerate or sicken, go mad, or transform into something worse. They need to delve to survive.
LONG STAIR Research Edit
After prolonged investigation and studies of fitness reports going back to the first forays into the Basement, a correlation was found between time spent in the Dungeon and the physical abilites of studied personnel.
Three teams were studied over a year long period. A group of marines stationed in Iraq (A), a Second Landing logistics team (B) and a Third Landing Security team (C). These groups were chosen because of a relatively similar range of physical abilities. Over the testing period a series of physical and psychometric analyses were performed. Group A remained within normal parameters based on the initial tests.
Group B showed some slight physical improvement. A 2% increase in response times and lifting strength and a 3% decrease in their assault course time. The more notable change was in their learned skillsets. All members in group B had applied for addtional training courses and 60% of the group showed a tendency to learn skills previously possessed by other members of the team.
The most significat changes occured in group C. They had a 12% increase in response times and lifting strength and an 8% decrease in their assault course time. Their skillset improvement was just as impressive as group B. There was a distinctly different focus for this team though. Upon compartive testing it was shown that the units corpsman now performed medical procedures that would be complicated to an experienced surgeon. The stealth skills possessed by the unit were remarkable. One researcher suggested that they would be capable of passing special forces selection with ease. There were also worrying psychological findings among group C. When engaged with xenofauna a large number of the unit would prefer using CQB techniques and looted weapons rather than maintain SOP.
Theories about this phenomena are abundant. Does interaction with the Basement grant physical and mental benefits at the cost of psychological health? Is this increase in abilities connected with depth, like distance does time compress more the further you go down? Or is it smilar to Hybrids? Is interaction with Basement denizens having some passive effect that builds up with time?