but is this true? do the studies really show this? senator miller would probably be dismayed to learn that there is no evidence whatsoever that children of gay parents turn out any worse than children of straight parents.
american psychological association:
In summary, there is no evidence to suggest that lesbians and gay men are unfit to be parents or that psychosocial development among children of gay men or lesbians is compromised in any respect relative to that among offspring of heterosexual parents. Not a single study has found children of gay or lesbian parents to be disadvantaged in any significant respect relative to children of heterosexual parents. Indeed, the evidence to date suggests that home environments provided by gay and lesbian parents are as likely as those provided by heterosexual parents to support and enable children's psychosocial growth.
It should be acknowledged that research on lesbian and gay parents and their children is still very new and relatively scarce. Less is known about children of gay fathers than about children of lesbian mothers. Little is known about development of the offspring of gay or lesbian parents during adolescence or adulthood. Sources of heterogeneity have yet to be systematically investigated. Longitudinal studies that follow lesbian and gay families over time are badly needed.
With the exception of studies at a few universities with very close connections with conservative Christian denominations (like the Brigham Young University in Salt Lake City, UT), essentially all research studies into same-sex parenting reveal that children of these families develop normally. There is some indication that boys are less sexually adventuresome, and that girls are more sexually daring. There are also anecdotal accounts of children having to endure ridicule, taunting and harassment from other youth because of their parents' sexual orientation.
a simple google search turns up tons of similar links, like this, this, this, and this. and that's just from the first page of search results!
unfortunately so far i can't find evidence of what steph says: "In fact, studies show the exact opposite; that children raised in households with single parents or with two parents of the same gender do just as well, are just as happy and well-adjusted as kids that grow up with a mom and a dad."
to be sure, studies seem to show pretty consistently that children raised by gay parents aren't any worse off than those raised by straight parents. but there are a lot of studies pointing to disadvantages of single parenting. it's entirely possible—and believable—that the majority of these disadvantages come from (1) economic difficulties inherent in many single-parent relationships (as the bulk of single parents are low-income mothers) or (2) the impact of divorce rather than any innate flaw in single-parenting arrangements. this makes a lot of sense, as obviously the biggest disadvantage of a single-parent home is that there is only one source of income, and the parent is likely to be gone for much of the day while they're out earning that income. but in my (admittedly limited) reading i can't find studies that account for that... perhaps it should be left to someone with more experience in analyzing empirical sociological studies. ¶