What the scientist who did the referrenced study did not take into consideration is that reactions to odors can be a learned response. The study does not prove or even indicate that gay men are genetically predisposed to be gay. With all due respect to Tuppence's use of Romans 1:26-27 as a possible indication of homosexuality being genetic I must disagree.
Romans 1:20-27
20 For since the creation of the world His invisible attributes, His eternal power and divine nature, have been clearly seen, being understood through what has been made, so that they are without excuse. 21 For even though they knew God, they did not honor Him as God, or give thanks; but they became futile in their speculations, and their foolish heart was darkened. 22 Professing to be wise, they became fools, 23 and exchanged the glory of the incorruptible God for an image in the form of corruptible man and of birds and four-footed animals and crawling creatures.
24 Therefore God gave them over in the lusts of their hearts to impurity, that their bodies might be dishonored among them. 25 For they exchanged the truth of God for a lie, and worshiped and served the creature rather than the Creator, who is blessed forever. Amen.
26 For this reason God gave them over to degrading passions; for their women exchanged the natural function for that which is unnatural, 27 and in the same way also the men abandoned the natural function of the woman and burned in their desire toward one another, men with men committing indecent acts and receiving in their own persons the due penalty of their error. NAS
Verse 26 begins "For this reason God gave them over to degrading passions". For what reasons? Those found in the preceding verses.