Whether people will put themselves into positions of doubt, performing acts which could create a prohibition regarding themselves or their property: Nedarim 18b-19b
Whether a person would perform a sinful act, if he could just as easily perform a permitted act: Ketuvot 72b-73b; Sotah 7a; Temurah 27a
If a person performs an act which involves a sin, do we assume that he would also perform another sinful act: Beitzah 15a [stealing and desecrating phylacteries]; Temurah 27a
Is it possible for a person to establish his status [Chazakah] as a person who will sin: Temurah 27a
Once someone sins, the transgression becomes easier for him to do in the future: Yoma 86b; Moed Katan 27b; Kiddushin 20a, 40a
People don't act when they know that their actions will be legally ineffective: Bava Metzia 15b [2x]
Whether people are more careful in dealing with outright prohibitions, or with a prohibition [against benefit from an item] which they create [in a vow]: Nedarim 15a
People naturally avoid contact with Holy Property: Pesachim 6a
People don't sin for someone else's gain: Bava Metzia 5b
A man having sexual relations assumes that it is under the same legal circumstances as he had when he married his wife: Yevamot 110a
If a man's wife checks herself for menstrual blood before sexual relations, he will become concerned and he will be less likely to approach her: Niddah 3b, 12a [2x], 65b
People will avoid violation of oaths, even if they are willing to take money which isn't theirs: Bava Metzia 6a
