Two quotes which appear to be true, together with civgene’s behavioural pairs, define the cause of addiction.

“The opposite of addiction is connection” — Johann Hari JRE #1250
“freedom means the absence of coercion” — Milton Friedman

Unique human behaviours pairs compare unique human partial cooperation with the strict competition in the animal kingdom.

Property – Identity of an place, item, or accomplishment belonging to a being or a group.  Honoured and understood as a provision of autonomy to a distant time.
Territory – Control of a place, item, or role by a being or group.  Enforced by violence.  Revoked by absence.

Investment – Dedication of time and calories into a being’s or a groups creative development.  Requires property and currency to realize return.
Assignment – Dedication of time and calories into another’s territory with the expectation of favour.

Freedom – A cooperative model of non interference.  The promise of non interference in exchange for a return of the same.
Treaty – A stalemate, a mutual temporary cessation of conflict to avoid over exertion.

Friendship – The expectation of continued freedom between parties despite periodic violation of it.
Alliance – A temporary teamwork towards and depending on a common goal.

Freedom means the absence of coercion.
Territory is a component of Assignment.
Coercion is a variation of Assignment.
Assignment displaces freedom

Addiction is a deficiency of connection?
(Non familial) connection is possible because of friendship.
Addiction is caused by the lack of availability of friendship
Friendship requires freedom.
At the root, addiction may be caused by a lack of freedom.

Assignment is a psychopathic work alike for Investment.
Assignment displaces Investment
Investment is displaced by the same forces that cause addiction.
Statistically, addiction and investment should be inversely correlated.

Seems obvious in hindsight, correct?  Behavioural pairs can be used to derive core human behaviours, including their rights, and the consequences if they are violated.  A somewhat common, but difficult to argue conclusion becomes much more clear.

It’s important to note that someone might condemn Hari based on the apparant implication that addicts have bad friends.  The problem is that friendship requires freedom to fully function.  Personal prisons can damage or destroy freedom beyond a friends control, no matter their qualities.  Like mental illness, abject poverty, or abusive parents not remediated by their state or society.  Sadly freedom may be a natural human right, but it’s not a guarantee.

Edit: Reworked faulty logic to different causality.

Edit 2: Improved quote source, added warning about friendship.