This stuff interests me to no end. But I understand bupkis about the mechanics of it. I guess I will wait till it comes on the science channel so as to get the readers digest version.
You might as well study the Nazi’s anti gravity flying saucers...or perhaps Charles Hapgood’s Hollow Earth Theory. All equally valid.
It's like having identical twins with absolutely no differences, and they themselves do not even know who is who(m). When you combine the wave functions of those two particles, they can be either symmetric or antisymmetric when the positions of the two particles trade places.
Particles that pair in systems that give rise to antisymmetric wave functions are called fermions. Particles that pair in systems that give rise to symmetric wave functions are called bosons.
Systems made up of very large numbers of fermions must essentially have one energy level for each particle in the system (this is not exactly true -- there is a complication but it doesn't change things much conceptually, so read on.) Systems made up of very large numbers of bosons do not need to have more than a single energy level for ALL of them (they usually do, but they don't HAVE TO.)
At all but VERY LOW temperatures, there are many energy levels available, so systems composed of many fermions at high temperature look just like systems composed of many bosons at high temperature. But, as the temperature falls, there is less and less energy available (that is actually nothing more than the microscopic definition of temperature.) This means there are fewer and fewer energy levels to occupy. For bosons, this is not a problem, because all of the bosons can occupy the same energy level if they have to. However, with fermions, each fermion must have its own energy level, so no matter how low the temperature goes, there are fermions "locked" into higher energy states.
Think of fermions like this: your kids are not grown up, and they get to bickering in the back seat when they touch each other (Dad! He's touching me!) You may have a van with three rows of seats that theoretically holds nine kids, but because of the Notouchy Effect (Pauli Exclusion Principle) the kids must each have their own row of seats, so your car can hold no more than three kids, if your kids are fermions.
On the other hand, the Brady Bunch kids are all perfect and love each other and are willing to sit in each others' laps if necessary. You can fit all six Brady kids all into the same row. Those are bosons.
Because systems with large numbers of fermions must fill large numbers of quantum levels, even at low temperature, they behave much differently than systems of bosons, all of which are willing to fit into the lowest available state.
[Now there is one very slight omission I promised to get back to: two fermions with the same "spin" quantum number are not actually in the same state even if they have the same energy. Quantum spin for fermions can have one of only two possible states. So in fact, each energy level for fermions can contain two, not just one particle(s). The idea is still the same.]