Part I: A Combination of Heredity and Environment…with the Emphasis on Heredity
Nothing compares to having a loving, friendly, kitten to place. Imagine only having to worry about the people you are placing him with—you know the kitten will be alright if you do a halfway decent job on your part. Or think of it from the owner’s point of view; how many times have you heard, “My Bengal is friendly but he doesn’t like to be picked up?” How many times have you heard, “My Bengal runs and hides when people come into the house—even friends?”
Three years ago I started working on the problem, because the Bengal can be the friendliest of cats. The Domestic Cat: The Biology of Its Behavior,a contains discussions and examinations of studies about nature and nurture, or as I prefer to think it, heredity and environment. My current thinking on friendliness was based largely, though not entirely, on the studies presented in the book.
Heredity
The reason this post has “A Combination of Heredity and Environment…with the Emphasis on Heredity” as a subhead is that heredity is the bottom line. For instance, your genes give you a certain maximum height; a bad environment can make you shorter but never taller. Your genes give you a certain maximum intelligence; your environment can make you as smart as your genetics will let you go but never more. And so it seems to be with cats—the effect of “friendliness” is first of all genetic, and only modified by environment!b

Three friendly bengal breeders (two queens with a stud in the middle) who pass their genetic tendancy for friendliness on to their kittens. (Here they are having a "Group Groom.")
As expected, the studies show the friendliness of the mother has an effect on the friendliness of the kittens (though it is hard to say from the report given of the studies whether this is genetic, environmental, or a combination of both). However (and a total surprise to me!), the studies show that the father has an effect on the friendliness of his kittens—even when the kittens have never come in contact with him! (For example, if the queen had had stud service at another cattery and returned home before giving birth.) This shows a clear basis for the inheritance of friendliness based on inheritance, not environment—apparently something he is passing along in his genes makes his offspring friendlier (or, as The Domestic Cat says, “it is likely that genetic factors mediated this effect”).
If it is true of the father, it also seems that friendliness is likely to be (at least partly) genetic in the case of the mother as well; there just hasn’t been a way to study it clearly, as there has been in males. Certainly in my experience, breeding a friendly stud to an unfriendly queen, or a friendly queen to an unfriendly stud, produces the same spread among their kittens, ranging from moderately friendly to very unfriendly. If you think about it, you will probably realize from your own program that certain combinations of stud and queen have more friendly kittens than different combinations of stud and queen.
Based on these studies and experience, it seems apparent to me that the cats with the highest genetic level of friendliness are those that are the offspring of two friendly cats. This is the theory I am applying at the moment to my breeding program.
Environment

This kitten is the offspring of two genetically friendly cats. She has only been socialized a few minutes each day, but her heredity makes her perfectly at home with vets or anyone else.
In addition, each kitten needs to be handled 30–40 minutes per day. Again “there seems to be an upper limit of about an hour per day beyond which further handling no longer produces dramatic effects.” Also, if the mother is present and has been socialized to humans, her “calm presence may reduce the kitten’s anxiety (build up its confidence), allowing exploration of the environment…and through this, may actually facilitate establishment of a relationship between the kitten and human.” [Quotes are from The Domestic Cat.]
I started socializing my kittens in accordance with these principles in 2003 or thereabouts, and in doing so I began to produce an overall more friendly, but somewhat mixed, bunch of kittens. However, now that I have started breeding only genetically friendly cats, the kittens have been (almost) perfectly friendly. This method of socialization works very well as a second tier to heredity to produce friendly kittens.
An additional advantage of using heredity and environment together is that I don’t have to spend as much time socializing kittens. In fact, I can socialize up to six kittens at once (rather than spending 30–40 minutes per day per kitten). Some days I don’t do much more than say “hi” to the kittens and they still turn out great. The heredity takes care of a lot of socialization!
Results So Far

Having two friendly parents means that the socialiation period takes less time and effort (for instance, each kitten requires much less than 30-40 minutes of interaction per day). Here are three kittens playing with my legs (ouch!).
How do I know if a stud or queen I’m thinking of adding to my program is friendly? After all, “friendly” is a term that means different things to different people. For example, nearly all breeders say their cats are friendly, and perhaps they are friendly to them, but they may run and hide from someone else, they may have problems being held… I try to look for the cats that are demonstrably friendly.
For friends, I may know their cats and which are suitably friendly. If I don’t know a breeder’s cats personally, I ask for specific pictures. If a breeder can send me pictures of both the adult parents of a prospective breeder kitten being held calmly by a relative stranger(s)—a vet tech, for instance—I accept that it’s truly friendly and not just friendly with its breeder. (They have to be pictures of the adult parents, not of the prospective breeder kitten, because anyone can forcibly hold a kitten.)

This cat might possibily be one that is demonstrably friendly. Numerous show cats may have the potential, although the best way to tell is pictures of the parents.
I have turned over all my breeders except one now, replacing those that were not demonstrably friendly with those that are, and that “old style” cat is ready to be spayed and petted out. I’ve made several mistakes along the way. For instance, two years ago I bought a queen who was just not friendly enough. I had to spay her and place her in a home before she ever had her first litter. Such mistakes are a little expensive, but I feel that in the long run they are a lot less expensive than producing kittens that are hard to place because of unfriendliness.
The selection of cats on the basis of “Friendliness First” may sound as though it narrows my choice of bloodlines disastrously, but not so! There are many cats, some from the most valued lines in existence, that meet this definition of demonstrably friendly. In fact, some of the cats that win the highest awards at shows meet this definition because to be a good show cat often means that the cat has a demonstrably friendly personality.
So I’m not losing a thing and I’m gaining cats that are wonderful in their sweetness as well as their looks. “Friendly animals are relatively easy to place permanently,” as The Domestic Cat says, but more importantly, superior friendliness is good for the breed in general. It will make a difference—maybe THE difference— in how our breed is viewed years from now. All it takes is a pair of demonstrably friendly parents and some socialization.
BUT!

This kitten's father (shown) and mother have both passed on their friendliness to the kitten. If she becomes a breeder, she will pass on her half of the genetic tendancy to her offpring, and they will pass on what they inherit from her and their father, and so on through the generations.
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a The Domestic Cat: The Biology of Its Behavior, second edition, Ed. Dennis Turner and Patrick Bateson, Cambridge University Press, 2000.
b Genetics and environment are interwoven in vastly subtle ways, making it difficult to say a trait is either hereditary or environmental. This post is my view of friendliness in cats; others may have different views.
Copyright March 2011 by Nancy Prince. All rights reserved.
You might find a National Geographic article interesting, as it tends to confirm everything you have independently discovered via familiar inherited “friendliness”. The article is “Designing the Perfect Pet” in the March 2011 issue. The researchers were in Novosibirsk, Siberia and they worked with foxes, but the similarities are striking!
Thank you,Glory! I’ll look it up.
Very good read. My Bengal is friendly but does not like to be picked up, no matter how much I socialize her she does not like it. Gives me excellent characteristics to look for. Thank you!