首先，同性恋不是选择，不是行为，而是身份。一个同性恋和异性结婚，发 生性行为，生子，他/她还是只对同性有性冲动，还是同性恋。说禁止同性恋， 就如同说禁止黑人，禁止左撇子一样可笑。改变性倾向的尝试从来就没有被医学 界认为成功过，一个例子也没有。已知的是，这种" 治疗"将导致心里状态恶化， 甚至自杀。同志需要的是认同和健康引导，而国内虽然常有声称有成功案例的医 生，可就如我前面说的，正儿八经的被医学界承认的没有，副作用大把，假如怀 着侥幸心理去尝试，请明白这是拿人做一个至今只有失败例子的实验。
其次，同性恋不是病，它并不是失败教育的结果，也不使人品行恶化。更没 有人因为接触同性恋者就变成同性恋，相应的，同性恋哪怕一辈子都只和异性恋 呆一起，他／她还是同性恋。性倾向不由意志转移，也不是由他人和社会造成的。 导致一些同性恋人士痛苦的不是同性恋本身，而是他面临/他认为将面临的歧视， 目前对他帮助最大的，是来自亲人的“无论你喜欢同性还是异性，我都支持你” 一句。
最后，禁的结果是，同性恋和不相爱的人结婚，伤害了另一个无辜者及其家 庭。如果以为所有同性恋的家长都接受不了，是大错特错，真爱可以克服偏见， 只有试图给孩子强加意志，不顾孩子真正幸福的父母才会顽固不化。
美国心理学会有个FAQ，不过链接不太好找：
http://www.apa.org/topics/orientation.html
挑几个短的：
Is Sexual Orientation a Choice?
No, human beings can not choose to be either gay or straight. Sexual orientation emerges for most people in early adolescence without any prior sexual experience. Although we can choose whether to act on our feelings, psychologists do not consider sexual orientation to be a conscious choice that can be voluntarily changed.
Can Therapy Change Sexual Orientation?
No. Even though most homosexuals live successful, happy lives, some homosexual or bisexual people may seek to change their sexual orientation through therapy, sometimes pressured by the influence of family members or religious groups to try and do so. The reality is that homosexuality is not an illness. It does not require treatment and is not changeable.
However, not all gay, lesbian, and bisexual people who seek assistance from a mental health professional want to change their sexual orientation. Gay, lesbian, and bisexual people may seek psychological help with the coming out process or for strategies to deal with prejudice, but most go into therapy for the same reasons and life issues that bring straight people to mental health professionals.
What About So-Called "Conversion Therapies"?
Some therapists who undertake so-called conversion therapy report that they have been able to change their clients' sexual orientation from homosexual to heterosexual. Close scrutiny of these reports however show several factors that cast doubt on their claims. For example, many of the claims come from organizations with an ideological perspective which condemns homosexuality. Furthermore, their claims are poorly documented. For example, treatment outcome is not followed and reported overtime as would be the standard to test the validity of any mental health intervention.
The American Psychological Association is concerned about such therapies and their potential harm to patients. In 1997, the Association's Council of Representatives passed a resolution reaffirming psychology's opposition to homophobia in treatment and spelling out a client's right to unbiased treatment and self-determination. Any person who enters into therapy to deal with issues of sexual orientation has a right to expect that such therapy would take place in a professionally neutral environment absent of any social bias.