Now, of course, I recognize that the evidence and arguments for evolutionary science are powerfully persuasive. But perhaps as a result of my youthful enthusiasm for creation science, I think that the best way for public high school biology teachers to handle the topic of evolution is to "teach the controversy"--to allow their students to survey the evidence and arguments for all sides in this debate, and then to leave the students free to make up their own minds. If I were a high school teacher, I would do what I do in my university teaching: I would indicate why I think the case for evolution is persuasive, while encouraging the students to compare the alternatives, with confidence that most students will see that the weight of the evidence and arguments favors evolution.
Occasionally, I have had my university students actually read Darwin himself--particularly, The Origin of Species and The Descent of Man--along with some contemporary writing on evolutionary science and some of the criticism coming from proponents of creation science and intelligent design theory (such as Michael Behe and Bill Dembski).
My students see that Darwin himself believed in "teaching the controversy." He presented the issue as a choice between two theories--the "theory of creation" and the "theory of natural selection" (or the "theory of descent with modification"). In defending his theory, he admitted that there are "a crowd of difficulties" for his theory. "Some of them," he lamented, "are so grave that to this day I can never reflect on them without being staggered" (Origin, beginning of Chapter 6). In fact, these "difficulties" turn out to be the very objections to his theory that have been made by the proponents of creationism and intelligent design. Darwin devoted much of the Origin to answering these objections and pointing to the weaknesses in the alternative "theory of creation."
Darwin also concluded--in both the Origin and Descent--that there is no necessary contradiction between his theory and religious belief. In the concluding chapter of the Origin, he declared: "I see no good reason why the views given in this volume should shock the religious feelings of any one." He quoted a remark by the Reverend Charles Kingsley: "it is just as noble a conception of the Deity to believe that He created a few original forms capable of self-development into other and needful forms, as to believe that He required a fresh act of creation to supply the voids caused by the action of His laws."
His famous last sentence of the book evoked the image of the Creator as First Cause, borrowing language that echoes the Biblical book of Genesis: "There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved."
This opens the possibility of a theistic evolution for those students who seek a reconciliation of religious belief and evolutionary science.
Although I think this would be the best way to teach high school students about evolution, I have found few high school teachers who agree with me. But, then, for a long time, it has been hard for me to get a clear picture of how exactly evolution is taught in American public high schools.
Now, a new book has gone a long way in clearing up my confusion about this--Michael Berkman and Eric Plutzer, Evolution, Creationism, and the Battle to Control America's Classrooms (Cambridge University Press, 2010). Berkman and Plutzner are political scientists at Penn State University who have used empirical research--particularly, opinion surveys of the general public and of teachers--to study how evolution is taught in American public school biology classes.
They make a good case for two remarkable conclusions. They show that the policies for teaching evolution in all the American states contradict what the majority of American citizens want, as reported in various opinion surveys. And yet, they also show that teachers have the discretion to violate state policies, and many of these teachers have done so in ways that conform to what the citizens in their school districts want.
Amazingly, while both the proponents and the opponents of teaching evolution have devoted most of their energy to trying to influence state educational policies, Berkman and Plutzner show that these policies have almost no effect on what is actually taught in the classroom, because regardless of state policies, the teachers decide what will be taught and how it will be taught.
There is a good reason why this debate over the teaching of evolution in the public schools has been an intense legal and political debate in the United States for almost a century--from the Scopes trial of 1925 to the present. The reason is that the fundamental premise of American political thought, as stated in the Declaration of Independence, is the equal liberty of all human beings, which apparently depends on the special moral status of human beings as created in God's image and endowed by their Creator with certain unalienable rights. If we believe that human beings are endowed by an evolutionary process with their distinctive human nature, does that sustain our belief in our special moral dignity? Or does any belief in the evolutionary origins of human beings from lower animals deny the necessary grounds of our moral dignity as rooted in "the Laws of Nature and of Nature's God"?
Although Berkman and Plutzner do not take up this deep philosophical question in their book, they do help us to understand how the moral and political debate over evolution works itself out in America's classrooms.
THE GAP BETWEEN STATE POLICIES AND PUBLIC OPINION
Berkman and Plutzer show us that public opinion surveys over the past thirty years indicate that the majority of Americans think that public school biology teachers should "teach the controversy." Most citizens think that in the debate over whether human and biological life originated through evolution, through divine creation, or through intelligent design, the public schools should present all sides to this debate.
In recent surveys, about 25% of the public would prefer the public schools to teach only creationism or only intelligent design. Only about 12-15% favor teaching only evolution, which has become the official policy in all fifty states in recent years.
This shows a great gap between public opinion and public policy. The primary cause of this gap is that public educational policy concerning the teaching of evolution has been constrained over the past 30 years by Supreme Court decisions, which seem to dictate that only evolution can be taught in public school biology classes, and that state laws for a "balanced treatment" of the evolution debate in public schools is an unconstitutional "establishment of religion."
In 1965, when I was hoping to debate evolution in my high school biology class, Susan Epperson--a high school biology teacher in Little Rock, Arkansas--launched a law suit against a 1928 Arkansas law that made it illegal to teach that human beings "descended or ascended from a lower order of animals." In EPPERSON v. ARKANSAS (1968), the U.S. Supreme Court ruled in her favor, striking down the law as an unconstitutional violation of the First Amendment, because it established a religious belief in creationism.
In 1981, Arkansas legislators tried a new legal strategy in passing a law mandated a "balanced treatment" of creation science and evolutionary science in the public schools, while also prohibiting any religious instruction. But then, in a Federal District Court case--McLean v. Arkansas Board of Education (1982)--a Federal judge struck down this law as unconstitutional, because it seemed to be an indirect way of teaching Biblical creationism.
The "balanced treatment" policy was also enacted into law in Louisiana, where it was required that if evolution was taught in a public school, creation science must also be taught as an alternative. In Edwards v. Aguillard (1987), the U.S. Supreme Court struck down this law as unconstitutional, because it seemed that the purpose of the law was religious rather than secular. Antonin Scalia and William Rehnquist dissented. Even in the majority opinion, there was one passage that left a slight opening for a "balanced treatment" policy:
We do not imply that a legislature could never require that scientific critiques of prevailing scientific theories be taught. . . . Teaching a variety of scientific theories about the origins of humankind to school children might be validly done with the clear secular intent of enhancing the effectiveness of science instruction.
This provided the opening for the intelligent design movement, which began with Phillip Johnson's Darwin on Trial (1991) and Michael Behe's Darwin's Black Box (1996). "Intelligent design theory" was said to be a purely scientific critique of evolution that was free of the religious associations of "creation science." And, thus, it could be argued that teaching intelligent design in a public school biology class as an alternative to evolution could be justified as purely secular instruction and thus not prohibited by the Aguillard decision.
This argument was tested in the Federal District Court case of Kitzmiller v. Dover (2005). In Dover, Pennsylvania, the school board enacted a policy that students in the biology classes should be told about a book in the library--Of Pandas and People--that would teach them about intelligent design theory as an alternative to evolution. Some parents and teachers sued the school board. Judge John Jones was persuaded by the trial that "intelligent design" was not really a scientific theory but a deceptive strategy for teaching creationism.
One dramatic piece of evidence for this was the history of the editing of the book Of Pandas and People. Prior to the decision in the Aguillard case in 1987, the book referred to the "creator" and "creation science." After the decision was released, these words were erased and replaced with "intelligent designer" and "intelligent design theory."
All of these court cases seem to make it difficult, if not impossible, for state educational policy makers to follow the public opinion favoring a "balanced treatment" of evolution and alternative theories. And although there have been some legislative debates over this in recent years, there seems to be a clear policy at present in all fifty states declaring that evolution alone is to be taught in the public schools.
And yet, as Berkman and Plutzer indicate, many teachers are free to ignore these state policies.
THE TEACHERS DECIDE
Much of what Berkman and Plutzer report in their book comes from a survey that they themselves carried out. In the spring of 2007, they conducted the National Survey of High School Biology Teachers. A survey form was mailed to 2,000 randomly selected high school teachers of biology in U.S. public schools, and 926 teachers responded, which included teachers from every state except Wyoming. In addition to answering the forced-choice survey questions, 325 of these teachers chose to add written comments.
As reported by these teachers, only one per cent never taught evolution. On average, teachers devoted about 14 hours of class time to evolution. 17% taught evolution in general but never talked about human evolution, apparently because it was too controversial. But 60% devoted 1-5 hours of class time to human evolution.
75% of the teachers report that they never talk about creationism or intelligent design in their classes. 22% report spending some time talking about creationism or intelligent design. 14-21% actually endorse creationism or intelligent design as valid science.
Berkman and Plutzer conclude that the most important factor in determining how teachers teach evolution is their personal beliefs about the subject. Of these 926 teachers, 31% believe in "organic evolution," the idea that "human beings developed over millions of years from less advanced forms of life, but God had no part in this process." 47% believe in "theistic evolution," the idea that "human beings developed over millions of years from less advanced forms of life, but God guided this process." 14% believe in "young earth creationism," the idea that "God created human beings pretty much in their present form at one time within the last 10,000 years or so."
Why do these biology teachers have so much freedom to follow their personal beliefs in deciding how to teach evolution? Berkman and Plutzer explain this by saying that high school teachers are "street-level bureaucrats"--government employees who act with broad discretion in their daily work with the public. They have so much discretion that they can disregard the policies handed down by policy makers.
This might seem to be contrary to democratic government if these teachers are refusing to execute the policies made by elected officials. But from another point of view, as Berkman and Plutzer argue, this manifests democracy from the bottom up rather than from the top down. In the United States, the public schools are highly decentralized. Each school district can be understood as a little democracy unto itself, governed by local community values. The teachers hired in each school district tend to be people who are comfortable with the cultural values of the community. Consequently, the teaching of evolution in the public schools tends to reflect the preferences of the local community. In rural and suburban school districts in the South and Midwest with traditional cultural values, there's likely to be some community preference for teaching creationism or intelligent design as an alternative to evolution, and the teachers in those districts are likely to reflect that preference, as opposed to the situation in urban school districts in the Northeast or West with more cosmopolitan values, where the local community is probably opposed to teaching creationism or intelligent design.
So who decides how evolution is to be taught in America's public schools? The teachers decide. But the local community also decides, because the teachers tend to conform to the cultural values of the community.
So how many teachers follow my approach--arguing that the evidence and arguments favor Darwinian evolution, but allowing students to weigh this against the alternatives?
Berkman and Plutzer report that of those teachers who introduce creationism or intelligent design into their classes, many say that they take a "teach the controversy" approach--presenting alternative ideas and leaving students free to arrive at their own conclusions. In fact, most of those who "teach the controversy" personally endorse creationism or intelligent design. Some teachers say that they tell their students that they need to understand evolution, but they don't need to believe it.
Of those teachers who say that they don't personally endorse creationism or intelligent design, 17% report that they raise the question of "irreducible complexity" as a possible objection to evolution, apparently acting as a devil's advocate to provoke thought in their students.
Of the 926 teachers surveyed by Berman and Plutzer, 13 identify themselves as proponents of evolution who nevertheless think it's important to present creationism or intelligent design as alternatives for their students to consider (190-191). For example, one teacher from Ohio explained: "I consider myself strongly on the side of evolution, but I do recognize the validity of creationism, and more importantly, I recognize that we have an obligation to expose students to both."
These are the only teachers who take my approach, which was also Darwin's approach, in defending the "theory of evolution" as superior to the "theory of creation," while taking seriously the "difficulties" for evolutionary theory, and arguing that evolution can be compatible with believing in the Creator as the First Cause of a universe open to evolutionary development.
Some posts on related topics can be found here, here, here, and here.