Important to Initiate Relationships at Work. Really?

I’m not at all sure about this Daily Stat from HBR: Why It’s Important to Initiate Relationships at Work.

I guess there is more data behind the headline (which I don’t really doubt), but the facts in the post don’t support the headline.  The post focuses on the bottom quartile of a ranking of employees’ willingness to initiate relationships (such as inviting co-workers for a drink) and finds that only 5% of the bottom quartile were “extremely engaged in their work, and just 7% had been promoted in the past year”.  In [all] other quartiles, about 40% had been promoted.

As is often the case in such things, the causality is not at all clear.  It could equally be that the bottom quartile were the most disengaged and therefore did not wish to enjoy relationships with co-workers.  The data given certainly doesn’t show that initiating relationships begets happiness, engagement and promotion.