In the movie Dumb and Dumber, Lloyd, played by Jim Carey, asks the lovely and sophisticated Mary Swanson, played by Lauren Holly, what the chances are of his becoming her boyfriend. She honestly responds, "One out of a million." After a moment of contemplation, Lloyd sports a broad smile and exclaims, "So you’re telling me there’s a chance!"

Reckless optimism is funny in the movies. But it is a sad commentary when Michigan adopts this stance in relation to our children’s high school education. Such is the case with the new high school graduation requirements in the state, known as the Michigan Merit Curriculum (MMC). The MMC requires that every high school student, beginning with this year’s ninth grade class, successfully complete four years of English and math, three years of science and social studies, one year of health/physical education and one year of visual or performing arts. Required classes include Chemistry, Algebra 2 and Geometry.

For those students who cannot complete the MMC, public schools are forbidden from offering them a diploma. They may be given the consolation prize of a "Certificate of Completion," but not a high school diploma. No longer will some students choose a college prep program and others not. Now every student will be taking college prep classes.

High expectations are an important part of encouraging students to do their best. Students from all socioeconomic levels and from all ethnic backgrounds, even those with limited English language experience, should be expected and encouraged to perform at their highest level. And it is critically important for public high schools to promote education as one of the keys to personal success and social equality.

But even high expectations must be tempered by the reality of ability. The maxim that "anyone can do anything" is simply not true. And while it may be the stuff of inspirational pep talks, the myth that any student can master any educational challenge can quickly be disproved. Curiously, we readily admit variations in ability when it comes to physical skills or other talents. Imagine if the MMC included the standard that "every student must run the mile under six minutes", or "all students must be able to create a realistic and accurate self portrait using acrylic paints."

While psychologists will point out that half of the population will score below average on any measure, the MMC seems based on the belief that we can somehow push everyone into the "above average" category. As designed, the MMC will selectively punish school districts that serve more "at risk" and special education students.

Further, the Bureau of Labor Statistics forecasts only a 1 percent increase in jobs requiring a four-year degree in the next eight years, while demand for skilled trades workers is expected to grow. While it is clear that high school graduates can no longer expect to enter the job market immediately, it is also clear that post-high school education can and should take many forms.

The MMC naively sets minimum graduation standards equal to and in many cases beyond entry requirements at four-year institutions. The coursework dwarfs the requirements of any community college or technical school. Students simply do not need to complete the MMC model in order to be successful in any number of educational settings after high school.

To understand how the MMC will affect students, imagine these scenarios:

• Susie wants to enlist in the U.S. Navy, but if she doesn’t pass chemistry, she won’t get a diploma and won’t be allowed

• Tom’s dad owns an auto repair garage and Tom plans to join the business. But since he failed Geometry, he will not get a diploma and won’t be able to attend an automotive technical school to become a certified mechanic.

• Julie has always been a slow learner, but she’s gifted in working with young children. Unfortunately, she cannot pursue post-high school education in early childhood care without passing Algebra 2.

And do we really believe that all students who aspire to become fire fighters, custodians, cosmetologists, or computer technicians need to master higher level math and science? By ignoring individual differences, the MMC will not only keep some of these students from getting a high school diploma, it will deprive them of their dreams.

In short, students who previously would have left high school and gone on to colleges or technical schools may no longer have that option. It is reasonable to predict that the MMC is going to increase dropout rates by discouraging students who struggle to pass required classes. Imagine what happens to a student’s motivation when he or she struggles to pass geometry, only to look ahead and see two more years of required math.

The solution to this problem seems simple. High schools should offer a two-tiered diploma. The MMC can be preserved and used for the large number of students who can obtain a "state-endorsed MMC diploma." But those unable to meet those standards should have the opportunity of obtaining a "district-sanctioned high school diploma."

At a time when we have begun to accept and understand the benefits of cultural diversity, we must also embrace ability diversity. Michigan public schools welcome every student who comes through their doors. Let us make sure that we also give them the chance to walk across the graduation stage and toward productive citizenship.

Michael D. Ruch, Ph.D., is a graduate of Hope College and the University of Wisconsin-Madison with 29 years of experience as a clinical and school psychologist in private and public schools. He currently works with Kentwood Public Schools and has a private practice of child psychology in Grand Rapids.