False statement.
Again, you're using the language of the Creationists. Biologists do not speak in terms of intelligence as an "accident". Either nothing is an accident (because everything that happens obeys natural laws--the laws of chemistry and physics) or everything is an accident (because there is no Creator, Intelligent Designer or Fine-Tuner intending anything).
In evolution, variation happens randomly (within the laws, again--for example, point mutations can be said to be random, but polyploidy is not). However natural selection is NOT random. So when you consider something like "intelligence", you have to look at a million advantageous changes that were selected for over a long period of time. Humans are not, in this regard, unique except that we occur at one end of the continuum of intelligence.
You're speaking of "intelligence" the same way some Creationists have argued that the human eye is irreducibly complex. In fact, "intelligence" refers to a host of mental capacities that exists to a greater or lesser degree in many organisms. Every one of these traits that natural selection favored helped the organism to have better reproductive success. Intelligence (and structures like the human eye) did not pop into being out of nothingness with no antecedents and no selective advantage on the way to some pre-defined end result.