The results of a recent Everett School District online survey about school start times are classic human nature — most parents prefer change that doesn’t affect their own kids. That is, no change for them. But change for others would be OK. That’s the way we are. The way we are routine-wired. No one can be blamed for not wanting to change a morning schedule that a family has mastered and works for them. Also, the survey allowed for leaving the schedules the same.

Transportation costs are driving the district’s look into possibly changing school start times. Traffic congestion is making it difficult for some bus routes to stay on schedule, so three new bus routes were added and four were modified, adding $163,000 to the $7.2 million transportation budget this year.

But the problem with trying to avoid “traffic congestion” is that it means earlier start times for high school and middle students. Here is a simple plea: Don’t do it. Don’t make those students go to school any earlier than they already do. As Sharon Salyer reported in Sunday’s Herald, “Time’s against them,” research shows many teenagers lack enough sleep, and if schools are changing start times, it is to make them later. Scientists say lack of sleep can affect mood, performance, attention, learning, behavior and biological functions. In other words, everything they need to do well in school.

Today’s students face academic and extra-curricular expectations like no other generation of students. It’s good that we expect more, but there has to be some balance. Despite our myth of the superhuman multi-tasker, who can do many things on little sleep, teenagers, who are still growing, for crying out loud, need a lot of sleep — 8½ to 9½ to meet their physical and mental needs.

Studies show the sleep- promoting hormone melatonin rises later at night for teens than it does in children and adults, and remain at a higher level later in the morning. A teen’s melatonin level, then, is at direct odds with a school day that starts before 8 a.m. Everett’s high schools currently start at 7:30 — if a new start time is adopted it would make it 7:10 a.m. That’s too early. Even if the melatonin stuff wasn’t true. (And students who participate in before school extra-curricular activities already start at 6 a.m. They certainly can’t go any earlier.)

Traffic can be bad, but we can’t let it dictate important changes like school start times. The school district asked, and got its answer. Don’t make the high school and middle school start times earlier.