Do bees have personalities?

Most folk would find the idea of bees having different personalities as absurd, but I suspect most beekeepers would disagree.
To be fair it may be a bit of an exaggeration to talk about personalities, but bees certainly exhibit different behaviours. You can see this with individual bees, but it becomes more obvious when you look at the behaviour of the entire colony.
My two colonies are totally different. East colony is neurotic; as soon as the temperature is above 8 centigrade they start flying. It's been 10 degrees or more these last few days and there has been plenty of activity.
In contrast West colony spends most of the winter hunkered down. You won't see them for weeks at a time and the only sign of life is the slowly changing pattern of wax cappings on the ground as the bees gradually eat through their honey store.
But last week's 'no varroa' count on West colony had me worried. No varroa could mean no bees, so I decided to remove the entrance block at the bottom of the hive and take a peek.
Dead bees littered the floor. I scooped them out and had enough to fill a coffee mug.
Despair and confusion followed. Surely they hadn't all died. I hefted the hive; it certain felt heavy enough so lack of food wasn't a problem. There's been enough rain so lack of water wasn't an issue either. What to do?
If I opened the hive to investigate further the cold could kill the bees and would certainly stress them. But then I remembered these bees have different personalities to the others, so I decided to wait and see.
Yesterday the thermometer showed 12 degrees, warm enough to tempt even this colony outside. I watched and saw one, then two, then several more bees leave and return through the hive entrance. I took the block off for another peek. Thank goodness - no more dead bees.
It's normal for a proportion of the bees to die as the winter progresses; fewer bees means fewer mouths to feed so winter stores can be eked out. But if the colony gets too small it won't be able to keep warm so there's an optimal balance. My guess is that the bees that died sacrificed themselves for the sake of the colony - truly altruistic personalities.