Age, they say, is just a number. Venture capital funding is also a number, and as it turns out, it’s closely correlated with age.

According to a new survey of U.S. startup founders conducted by the venture capital firm First Round Capital, the most prevalent bias investors have towards tech founders is based on age (37%), with gender (28%) and race (26%) running just behind, Quartz reports. Remarkably, 89% of the respondents agree that older people face age discrimination in the tech industry generally.

And age bias doesn’t simply affect those in their 60s or 70s—participants in the survey claimed ageism in tech begins, on average, at age 45. A quarter of the survey respondents maintained that bias starts as young as 36.  

And age bias doesn’t simply affect those in their 60s or 70s — participants in the survey claimed ageism in tech begins, on average, at age 45.

Research supports that age diversity leads to increased productivity and performance in the workplace. Statistics also show that older workers take fewer sick days, exhibit better problem solving skills, and take more satisfaction in their work than their younger counterparts.  

So why does ageism persist in the tech startup space?

There are many factors, but, as Quartz points out, the survey itself holds a clue. “[I]n the diversity-and-inclusion portion of the survey, First Round did not ask founders when they think the tech industry will be representative in terms of age,” the story notes. “Until we take ageism as seriously as other forms of workplace bias, every industry, especially tech, will hinder its own potential.”