Willravel

Precedence begs to differ. Humans moved in packs when we were hunter gatherers and I'd say we're doing okay. Most intelligent mammals (everything from wolves to dolphins to chimps) move in and live in packs (or troops or schools(?)). They are successful. As I said above, the individuals are actually stronger when they work together for common goals. I'll tell you what, hunt down and kill a wooly mammoth all by yourself with a spear. Difficult? Now try it with 12 of your best friends, all with spears. A bit easier? And what about all of the myriad of jobs that require specific skill sets. When you're in a pack, individuals can develop, explore and improve on skills ranging from cooking to hunting to making clothing. If you have one member of the group who has the opportunity to develop sowing skills alone instead of having to hunt, cook, protect him or herself, pick up and move, gather fruits/veggies/nuts, etc., etc., they can get more efficient and even inventive with their work. This provides a stable environment for progress. Imagine if your job is to hunt. Just to hunt. You can concentrate on strategy and weapons, technique. While someone else makes your shoes and maintains your encampment, you develop better ways to hunt.

BTW, I think it's a combination of caring for self and pack that really makes us so badass. There is a careful balance that tends to favor the more intelligent mammals like humans.
It's not an either or situation between individual and group development. Within the group, the more successful members tend to pass on their genes more. Still, cooperation is a survival trait.