I recently went on my second “culture tour” of a company’s headquarters in as many years. Last year, it was at Zappos outside Las Vegas, and this year I visited The Motley Fool in Alexandria, Virginia.

I recommend touring both offices if you happen to be in either locale. While they both have amazing employee benefits, amenities and policies that will blow you away, perhaps the most jarring thing you’ll find at both workplaces is how genuinely happy the employees are to be there.

I’m sure the employees at both company’s love the game rooms, nap rooms, free food and unlimited vacation, but I’m guessing that those perks are not the root cause of happiness at those companies. In fact, I did not see those perks being heavily utilized while I was on the tours (granted, I was at both offices pretty early in the morning). There is something deeper and less tangible going on than cool office spaces. I don’t have the exact answer, but my theory is that employee happiness at these two companies is the result of the companies having a culture that actually lives and breathes its core values.

Many companies list their core values but only pay them lip service. When employees are exposed to contradictions between company values and how things are actually done, there’s a subconscious, discordant force at play within the company which affects employee happiness.

I’ve felt that something’s-not-quite-right feeling at many companies, but not at all at Zappos and Motley Fool. Whether or not I’m on the right track with my theory, my visits to the two companies have stressed the importance of building a culture that is true to your company’s core values. I will make a deliberate effort to build that type of culture in my company and any future business.