The most interesting and rewarding conversations to me seem to be when there’s a balance between agreeableness and constructive arguments. The trend has been for males to lean towards argumentativeness (to establish status and to seek challenge/adventure), while females lean towards over agreeableness (to build acceptance and comfort, often at the expense of individuality), at least initially.

http://en.wikipedia.org/wiki/Language_and_gender#Speech_practices_associated_with_gender

One communication trick, if required, is to sandwich the argument(criticism) between agreements(complements).

agreement: hey, that’s great what you did.
argument: this portion though, would be better if you did XYZ instead…
agreement: …but apart from that bit I mentioned, overall, it’s all pretty excellent.

Sandwiching helps to get criticism past the “reptilian brain’s” automatic defences, so “higher brain” centres can have a chance to consider it.

Most post-secondary schools offer courses on critical thinking, but as the speaker said, it’s a little late at that stage.