China Gorman, a consultant who helps organizations connect HR operations to the bottom line, gave a presentation not long ago that shocked everyone in the room. She had cited a statistic from the Aberdeen Group’s Strategic Talent Acquisition Report.

Millennial employees go into new jobs expecting to stay at least 5 years, and yet they depart after an average of 1.5 years. The 1.5 years stat surprises no one, I’m sure. After all, everyone knows that Millennials are the most disloyal employees out there. They are known to use their free-wheeling twenties and thirties to pop in and out of organizations all over the place. Before you even have the chance to get a nameplate on their cubicle, they’re gone.

It was the first part of the Aberdeen stat that had us all aghast. Apparently, Millennials like and anticipate stability more than we thought. They look forward to staying at a company long enough to make their mark, develop professionally, and move up. So what’s going wrong between that initial acceptance of the job offer and the resignation that comes far sooner than anyone planned? Allow me to speculate on some potential causes.

Their expectations are too high

A Millennial goes into a new job – particularly a first job after college – believing it will be the be all, end all of career satisfaction. They will wow the higher-ups, save the company if not the world, and achieve stardom in a single bound. Unfortunately, this is not exactly how it works out, and they are gravely disappointed.

Companies have great branding

In the recruiting world, there has been a major emphasis on employer branding as of late. Organizations are pouring lots of effort and resources into showcasing why they are the best places to work. The only trouble is, often the reality doesn’t live up to the hype. Millennials jump ship because what the career experience they’re getting is vastly inferior to the experience they were promised.

Onboarding processes leave something to be desired

Most organizations have been slow to realize that employee orientation is more than just a half-day in a conference room and a folder full of forms. Millennial hires, who are prone to making quick and irreversible judgments about a new employer, will be ready to quit the minute their boss leaves them stranded in an empty office on their first day. True onboarding fully engages the team of the new employee and takes place over a period of weeks. Yes, it must be strategic, and yes, it must be planned well in advance.

They can’t move up

The Baby Boomers lost their retirement savings in the recession, and now they’ve bottlenecked the promotion pipeline for the Gen X-ers and the Millennials. Younger professionals aren’t going anywhere in many organizations until the Boomers finally vacate. The X-ers don’t mind as much right now because they’re busy with aging parents and growing kids. But the Millennials are far less patient.

Millennials, please chime in. How long did you stay at your last job? How long did you intend to stay initially, and what changed?