Looks like 401(k) participants are taking stick-to-it-ness to a new level, at least when it comes to target-date funds.

Research from the Employee Benefit Research Institute in Washington finds that roughly 90 percent of those investing in target-date funds in 2007 stuck with them in 2009. The rate was even higher for those auto-enrolled in them -- 95 percent.

EBRI's research also finds that younger 401(k) participants were more likely to use TDFs and continue to use them, than older participants.