In psychology, anchoring bias refers to the excessive influence exerted on our judgments by the first piece of information we're presented. For example, if the first price quoted for an item is very high, people will, on average, assume a greater value for an object than they would assume if the first price quoted is much lower. We use the initial information, the high price or the low price, as an anchor or reference point for subsequent judgments of value. This occurs even when the effect is explained to people and they're cautioned before they offer judgments.
In discussions of the George Zimmerman trial, the subject of overcharging and convicting of lesser charges has repeatedly been raised. The overcharge is the anchor that makes conviction on a lesser charge seem more reasonable in light of the evidence than it might have seemed had the accused had been charged only with the less serious crime at the outset.
This is regarded by some as a legitimate approach to prosecution, but what it really amounts to is exploiting a cognitive bias, deliberately causing people to make errors in judgment that fall against the accused.
Anchoring gives the prosecution a natural advantage because they get to set the biasing anchor in criminal cases. They won't always exploit this by overcharging, but it seems like we see enough overcharging that we ought to be far more concerned about wrongful convictions on lesser charges.
Perhaps conviction on lesser charges should be prohibited or veyr strictly limited. If prosecutors aren't sure enough of a case to bet it all on a particular charge, then maybe they shouldn't be bringing that charge into court. Charge what they have a rock solid case for--no more than that. This should not be about messing with jurors minds to convict people of crimes when the cases against them are weak.