Psychology Masters Program Destroying Relationships?

My son's ex-girlfriend just completed her first year of a psychology masters program. Out of the blue (for him), she ended their 8 year relationship showing almost no emotion. They had a couple rough patches recently but were talking about marriage and their future together. They have been living together for a couple years and she just signed a new 12 month apartment lease with him. She doesn't seem like the same person anymore. There is another guy she "has feelings for" but the whole thing seems very strange.

My son now told me that of the 30 people in the masters program, only 1 remains in a committed relationship. Not everyone was in a serious relationship but several engagements and serious relationships have ended. She said that one day in class she had an epiphany that she didn't love him anymore.

Can anyone shed light on what happens in these classes that would cause this kind of damage?