There is very little difference between primary and caucus voters, and also very little difference between caucus/general election voters as well. Primary/caucus voters tend to be older and a little more ideological (see quote below), and the size of the differences is almost exactly the same between caucus and primary voters.
There is an excellent paper that summarizes some of the behaviors you question, entitled Demographics of Primary, Caucus, and General Election Voters. The abstract is:
The objective of this research project is to analyze the demographic
characteristics of voters in Iowa, New Hampshire, and Ohio in order to
determine if there are significant differences between primary, caucus,
and general electorates and to investigate the consequences of these
differences for election outcomes.
And contains interesting nuggets like:
Nownes offers further support for this idea in his article “Primaries, General Elections, and Voter Turnout: A Multinomial Logit Model of the Decision to Vote.” Using data from the 1988 National Election Study, Nownes modeled the dynamics that led voters to vote on both the primary and the general election, only in the general election, or in neither the primary nor the general. He finds that “[there] is no evidence […] that primary voters are more efficacious,
‘dutiful,’ concerned about the election outcome, or informed, than other voters. In short, individuals who vote in both [primary and general] elections are not much different than individuals who vote only in the general election. Both sets of voters share many of the same characteristics” (Nownes 1992, 219). These findings call into question other studies concluding that primary voters are vastly ideologically and demographically distinct from the general electorate.