The compulsion to check scores every free moment is a bad habit that poisons a player's motivations and therefore ability to act in the interest of their team. I would know, as I've curbed most of that behavior away. Now I have a new goal: kill as much as possible as fast as possible to reduce the spawn tickets as quickly as possible (without becoming a liability).
I don't get jealous or angry when someone outscores me, but if they seem to be facerolling the enemies--lately that was the only truly successful Piranha user I've seen--then I become a bit perturbed, doubly so if the faceroller in question acts with apparent disregard for their teammates. Likewise, players who go off in Lala Land, sometimes chronically, when the rest of are working towards an objective also perturb me. If I'm doing the best on my team and they haven't gotten under my skin, then I will try to own them and their mistakes, in the best possible sense (i.e., "take ownership of"). On the rare occasion when I'm handily outscored, I am suspicious but also intrigued and wish to evaluate this other player's ability and strategy, as I would do in any game. Finally, when someone manages to maintain a score close to mine, then I do compete a little for top spot by focusing on my efficiency. IMO, those priorities are much more useful and slightly more rewarding than just shooting for top spot, whatever the cost.