I have heard that a Christian convert usually adopts the religious
belief sets of the denomination or group in which he or she has the
conversion experience.  Where can I see this study documented?  I want
to know who performed the study, what were the survey questions and
what were the statistical results.

I found something in an Australian study that argues against that
statement:
"People were more likely to go to where they were comfortable and felt
catered for, rather than their denomination of birth/conversion.
Denominational affiliation had in large part been replaced by a
‘Protestant Supermarket.’This was particularly true for those under
40, with only 15% viewing loyalty to one denomination for life to be
important compared to 38% for those over 60. This leads Kaldor to
suggest that many people with active commitments have ‘no great sense
that a nominal membership of a particular denomination should have an
overriding claim on their affections and loyalties.’"  The work cited
in this respect is Peter Kaldor, John Bellamy, Merilyn Correy and Ruth
Powell, First Look in the mirror: Initial findings of the 1991
National Church Life Survey, Lancer, Homebush West, 1992.  The study
is at http://www.geocities.com/Athens/Oracle/3499/asr494b.htm

I'm not sure that the Australian study necessarily contradicts the
thesis of the questioner.  I think what's changed over the past
generation or so in American Protestantism is that the distinctions
among demoninations are less than the distinctions among individual
churches.  When people move or otherwise decide to look for a new
church, they still look for the same type of church as where they had
a good experience.  These days, though, that church very well could be
in a different denomination (or no demonination at all).  At least
that has been my observation.

We are all searching for eternal happiness, and we are all searching
for the Source of all Happiness. When people who have been labouring
under a delusion have their minds strongly opened to happiness where
before there was only sadness, they are faced with a choice about what
to conclude. Do they conclude that the happiness comes because of
external circumstances, i.e. the group that they are in at the time of
the conversion, or do they conclude that the new happiness is the
product of a growth in their own ability to react well to their
surroundings? This, I feel, is the basis of your query.

For instance, if I eat oranges, and I only ever eat oranges, and my
life is not very good, and then one day I see you walking along,
happily eating an apple, I might suddenly be led to think, "How come
he's so happy?" I stop you and ask you "Why are you so happy?" and you
reply, "Because I'm eating an apple."

At this moment, I have a choice of logic to make. I can look at the
sensory data in front of me, what I hear and what I see, and conclude
that "Eating apples makes one happier than eating oranges." At that
point, I vow to devote my life to eating apples, and spreading the
apple-eating gospel.

On the other hand, if I choose to distrust your explanation; if I
conclude, "well, his being happy is a product of more than just eating
an apple; it's just that we have to use the imperfect phenomena of
communication," I can conclude, "eating apples does not necessarily
make one happier than eating oranges. Maybe I need to concentrate on
the good things in my life more. Then I might become happier." At that
point, I will not then become an apple-eating guru, but I might lose
the psychological chains which have kept me bound to my orange-eating
habit.

I would direct you to the works of Paramahansa Yogananda for an
inspiring discussion of religious beliefs, their formation and a
discussion of habit and the external trappings of religion. Especially
relevant would be Autobiography of a Yogi, or 'The Need for Universal
Religious Principles' in "Journey to Self-Realization", his collection
of essays and talks. Alternatively, you could visit
www.yogananda-srf.org for more information.

As a final thought, you do not need specialist studies to see how
people, converted or otherwise, cling to the external habits of a
particular group because they think that in it lies the key to their
happiness. Looking at the world around you, talking to those around
you, and examining your own principles and habits will inform you much
more.