Relatedness and Supersisters
An important factor in understanding hive dynamics is to have some idea of the inter-relatedness of worker bees within a colony. Apis mellifera queens mate with several drones exceptionally as many as 20.

The diagram below explains the different levels of commonality between worker genes that might be found in the workers of a hive. All calculations of genes in common are in relation to the worker that will finally emerge from "Worker Egg 1".

All workers in a hive will be at least 25% related as they have a common mother, Queen (A). It is not 50% inheritance from Queen (A) because only half of the genetic material from the mother is passed on. The Queen is diploid and carries two copies of each gene. In any egg it is down to chance which copy of any gene she passes on and which she does not. The other will come from the drone.
Scientific Beekeeping
The drone is haploid and only has one version of each gene so all his sperm will be genetically identical. The Worker Mother Queen (A) will have received many sperm from this Drone X. All of her eggs fertilised with Drone X's sperm will receive identical genetical material, so from the drone side, they will be fully identical. To calculate how identical the resultant worker will be you add the 25% from the Queen's egg to 50% from the drone's sperm to come up with 75% identical workers. These will be super sisters.

Queen A may have also mated with Drone X's brother, Drone Y. It is again purely down to chance which genes are passed on to any one drone. The chances are even that, for any one gene, Drone Y will have the same gene as Drone X therefore there will be an additional 25% common inheritance (the same as the egg side), so 50% identical genes between the AX workers and AY workers. They are known as full sisters.

Queen A will have mated with many other drones. Let's call one Drone Z. He had no common relationship with the other drones. Here a worker egg fertilised with his sperm will only have 25% in common with the genetic material of the workers described above, inherited from her mother Queen A.

You can see that there will be different levels of relatedness amongst the bees in any one colony ranging from 75% to 25%. Worker bees can identify their super sisters and form cliques within the hive.

It is said that the altruism observed in workers illustrates that they recognise that that their co-workers may be 75% related to themselves, more related than any drone that the worker herself could produce (50%).

Clique formation of super-sister honeybee workers (Apis mellifera) in experimental groups. Meixner & Moritz