To me, dark matter is matter. It looks like matter, it quacks like matter, it waddles like matter. It has many, many properties that indicate it's ma… - Frank Wilczek

Particles that, like ⁴He, show constructive interference are said to be bosons—a shorthand term for "particles obeying Bose–Einstein statistics." …One way to recognize bosons is their tendency to imitate one each other. ...the presence of one boson increases the chance that another of its identical siblings will also appear in the same spot. There's an attraction between them. We will speak ...of an attractive identity force drawing together identical bosons. Lasers are a spectacular example...

There is a simple rule for composite objects, such as nuclei or atoms. The rule is that if such an object contains an odd number of fermions, the composite object is a fermion. Otherwise, it is a boson. ...this simple rule doesn't care at all about the number of bosons in the composite object.

We evolved to be good at learning and using rules of thumb, not at searching for ultimate causes and making fine distinctions. Still less did we evolve to spin out long chains of calculation that connect fundamental laws to observable consequences. Computers are much better at it!