Pregnancy predicts sexual activity just as sexual activity predicts pregnancy (actually, better). The reference to the future is that you test the second variable in the future, not that it receives its value in the future.
From the second link:
> Predictor Variable: It does not imply causality. A predictor variable is simply useful for predicting the value of the response variable.
> Pregnancy predicts sexual activity just as sexual activity predicts pregnancy (actually, better).
This merely says that the use of "predicts" in this context is meaningless, since in common usage "predicts" implies a one-way relationship.
I see from your second link that a definition has been crafted that undermines the word's common meaning. So it goes in language, an art, not a science, and one in which words mean whatever people think they mean, as with the sad case of "literally", which often means "figuratively".
You're the one who specifically called out the use of 'the word "prediction" in this context'. If you're not familiar with standard statistical terminology, why try to start a fight over its use in statistics?
This merely says that the use of "predicts" in this context is meaningless, since in common usage "predicts" implies a one-way relationship.
I see from your second link that a definition has been crafted that undermines the word's common meaning. So it goes in language, an art, not a science, and one in which words mean whatever people think they mean, as with the sad case of "literally", which often means "figuratively".
http://www.merriam-webster.com/dictionary/literally