Relevant section from Steve Rayhawk's nursery effect link:

If an 0-99 range voter has given 0s and 99s to the candidates she considers most likely to win, and now asks herself "how should I score the remaining no-hope candidates?", the strategic payoff for exaggerating to give them 0s or 99s can easily be extremely small, because the probability of that causing or preventing them winning can easily be below 10^-100. Supposing a voter gets even a single molecule worth of "happiness neurotransmitter" from voting honestly on these candidates, that happiness-payoff is worth more to that voter than the expected payoff from exaggerating about these candidates via "approval style" range-voting. Therefore, range voters will often cast substantially-honest range votes, even those inclined to be "strategic."