Why the Dutch Grow Taller Than Americans

While the Dutch keep growing taller, people in the United States appear to be shrinking. The findings of a new study may explain.

The Dutch are currently the tallest people on Earth, reports a new study, due to natural selection as well as good environmental conditions in the Netherlands.

Since there is a connection between height and lifespan -- with taller individuals tending to live longer than shorter people -- lessons can be learned from the Dutch.

Most Dutch enjoy "low social inequality, good access to good health care (and) regular healthcare checks for children," lead author Gert Stulp told Discovery News. His team's research is published in the latest issue of the Proceedings of the Royal Society B.

Stulp, a researcher at the University of Groningen and the London School of Hygiene and Tropical Medicine, and his colleagues analyzed data from what's known as the LifeLines study. LifeLines has been examining the health and health-related behaviors of 167,729 people living in the Netherlands, covering several generations. The researchers also examined data on height over the past recent centuries.

In the mid-18th century, the average height of Dutch men was only about 5'4", based on military records. Now, the average height of men from the same region is over 6 feet. The average height of Dutch women is 5'8".

What's more, the Dutch are continuing to grow taller.

"The Dutch have shown a remarkable increase in height that has been rather linear with little evidence of leveling off, which itself suggests that the limit might not have been reached," Stulp said. "And further improvements in environmental quality may well mean that we see a further increase in height."

In contrast, some research suggests that people in the United States are now growing shorter on average. Currently, the average height of American men is about 5'10" and the average height of American women is about 5'4 ½".

"One reason may be the larger -- and increasing -- inequality in the U.S.," Stulp said. "Inequality leads to shorter heights, because the costs in terms of height of being poor are larger than the benefits of being rich."

He also said that natural selection could be favoring shorter heights in the United States. That isn't the case in The Netherlands, where the LifeLines study revealed that taller women experienced higher child survival. He explained that they could have more bodily resources to invest in their offspring.

Height was also consistently related to the number of children born, with taller people tending to have more kids.

Overpopulation and limited resources can keep human growth in check.

"Taller individuals require more resources, bigger planes, bigger beds and the like," Stulp said.

Not every region can therefore support such people, as a collective whole, over long periods.

Another factor is nutrition.

"A nice example may be the large quantities of milk and cheese products that the Dutch consume, which have been shown to have substantial effects on growth," Stulp said.

John Komlos, who has also studied human height, told Discovery News that he agrees with the primary findings of the new study, and pointed out that evolution by itself cannot explain what's going on in the Netherlands.

"If the tall Netherlands population was based on evolution, then why were they not already the tallest in the 19th century?" asked Komlos, who is a professor emeritus from the University of Munich.

"In other words," Komlos added, "the fact that they are the tallest today is due to their social policy: terrific health care provided for expectant mothers, social safety nets, etc. Otherwise, they would be only as tall as the British or Americans."

July 11, 2011 --

Eighty-six years ago, high school coach and occasional substitute teacher John Scopes went on trial for violating the Butler Act, a law passed in Tennessee in 1925 prohibiting public school educators from teaching their students about the theory of evolution. The case, The State of Tennessee v. Scopes, drew intense national scrutiny. Prior to the trial, the American Civil Liberties Union offered to defend any schoolteacher that violated the act. After reading instructing his class in Darwin's theory of evolution, Scopes proved a willing defendant. (Scopes even encouraged his own students to testify against him.) Dubbed the "Monkey Trial" by H.L. Mencken, who covered part of the proceedings for the Baltimore Sun, the case attracted a media frenzy, and led both the prosecution and the defense to recruit high-profile representatives for their side. In this photo, Scopes awaits the verdict on the final day of the trial, July 21, 1925.

The trial was not about a simple violation of a law, or even a debate about free speech and First Amendment rights. Rather, the proceedings were about the clash between two seemingly diametrically opposed worldviews: creationism and evolution. On the one side, there were the fundamentalists, who espoused the Biblical view of creation and were firmly anti-evolution. This group found a champion in William Jennings Bryan (right), a skilled orator and former presidential candidate. Bryan had long been involved in the anti-evolution movement and had given several speeches and lectures against Darwinism. Modernists, as they were called, advocated Darwin's theory of evolution. Clarence Darrow (left), a fierce litigator with a reputation of fighting for the underdog, represented this side.

In this photograph, Darrow questions Bryan directly, wherein Darrow repeatedly pressed Bryan to apply scientific standards to Biblical scripture. Prior to this exchange, Judge John T. Raulston, who appeared to favor the prosecution throughout the trial, had deemed all of the defense's scientific witnesses inadmissible. After several heated exchanges, Bryan's testimony was also expunged from the record by Raulston the following day. On July 21, Scopes was pronounced guilty, and fined $100. Although the prosecutors had upheld the Butler Act, the decision would be reversed in appeal, and the case turned the tide against government efforts to restrict the teaching of evolution in public schools. In 1967, Tennessee repealed the Butler Act.

Long before the Scopes trial caused a stir in the United States and brought the public attention to the theory of evolution, a debate at the British Association of Oxford in 1860, which featured Huxley and Bishop Samuel Wilberforce, an long-time opponent of Darwinism, caused an uproar among educated elites in the United Kingdom. During the debate, Wilberforce famously asked Huxley whether it was through his grandmother or grandfather that he claimed to be descended from a monkey. Huxley famously retorted that he is more ashamed to be connected with a man who used his talents to hide the truth than he would with a monkey. The debate served to popularize Darwin's theory of evolution within academic and scientific circles.

Although the Scopes trial was one of the most famous challenges to evolution, it was by no means the first or the last word in the debate between theologians advocating creationism and scientists who support the theory of evolution. In fact, even before Darwin published the "Origin of Species" in 1859 (and his follow-up, "The Descent of Man," wherein he tracks the evolution of humans specifically), critics, primarily driven by religious interpretations of the origin of the universe and specifically humankind, have challenged any views outside of the Biblical interpretation of creation. The notion that humans had descended from "a hairy, tailed quadruped, probably arboreal in its habits, and an inhabitant of the Old World," as Darwin wrote, was deemed radical in its time and met with strong resistance. Anti-evolution critics and prominent theologians frequently accused evolution supporters of denying the existence of God or the human soul, despite the fact that Darwin had described himself as an agnostic -- a term coined by one of Darwin's earliest supporters, Thomas Huxley -- and not an atheist. There were, however, early attempts to reconcile the religious view with the scientific one. Published in 1860, "Essays and Reviews" is a collection of seven essays that collectively opposes a literal interpretation of Scripture in response to Darwinism while holding God as the highest authority in the universe. Even with this seemingly conciliatory argument, a couple of the authors were accused of being heretics in 1960.

Prior to the Scopes trial, creationism was widely taught in schools and accepted as fact. Even in the aftermath of the Scopes trial, it remained illegal to teach evolution in Tennessee. In the 1968 case of Epperson v. Arkansas, the Supreme Court ruled that banning the teaching of evolution was unconstitutional since it meant public education would be tailored to religious preferences. Since evolution had to be taught in public school following this decision, a new effort was underway in states across the country: affording equal time to the teaching of evolution and creationism in classes, which almost suggests an equal sense of scientific viability with the two sides. In several subsequent cases, such as McLean v. Arkansas Board of Education and Edwards v. Aguillard, courts ruled against efforts to force public school teachers to offer "balanced treatment" to evolution and creationism.

The debate between evolutionary theory and creationism is not only about a rivalry between two competing theories; there's also a dispute among creationists about the proper interpretation of the book of Genesis. Liberal creationists argue that Darwin's theory of evolution, and subsequent scientific followups relating to the age of the universe, are true and accurate. They believe that the universe and all of creation formed and evolved over time, but that God was the mechanism through which the process began. These are called old Earth creationists. There are also progressive creationists, who believe that evolution did play a role in the formation of life today, but that God intervened periodically to create new life, rather than all at once some 13 billion years ago. Finally, there are the young Earth creationists, who date the origins of the universe from anywhere between 6,000 years ago and 10,000 years ago. Young Earth creationists are those typically identified with the creationist movement in general. Their beliefs essentially have nothing in common with Darwin's theory. In this photo, a visitor surveys the exhibition at the Museum of Creation and Earth History in Santee, Calif. It is one of several creationist museums around the country that openly educates the public about young Earth creationism.

With courts continually striking down the teaching of creationism as espousing a religious perspective in public education, creationists have worked to develop their belief as a legitimate alternative to evolutionary theory. Some creationists have even documented what they describe as scientific proof of young Earth creationism. On this site in Glen Rose, Texas, creationists claim that human footprints can be seen right beside dinosaur tracks, proof that both dinosaurs and humans coexisted. Further scientific study, however, has shown that the purported human footprints are in fact the result of a combination of elongated dinosaur tracks, erosion, and some doctored specimens of loose rock.

A petroglyph in a Utah cave that resembles a dinosaur has also been used by creationists as evidence of coexisted between humans and dinosaurs. An examination by researchers has shown that the drawing is in fact a composite of two non-dinosaur drawings as well as a mud stain, although at least one creationist has taken issue with the method the scientists used to examine the petroglyph.

With the courts repeatedly finding that creationism is a religious view rather than a scientific theory, creationists re-branded their belief as "intelligent design" in an effort to divorce the Christian overtones of creationism from the belief in a universe designed by a creator. The 2005 case, Kitzmiller v. Dover Area School District, struck down the teaching of intelligent design in classrooms in York County, Pa., with Judge John E. Jones III issuing 139-page decision finding that intelligent design was just creationism by another name and violated the Establishment Clause of the First Amendment. Despite the history of court rulings and the increasing acceptance among Americans of the theory of evolution, state legislatures across the country are continuing to push through bills advocating the teaching of creationism, or some derivative, in public schools. As of April 2011, nine bills concerning the teaching of evolution in seven states have been proposed. These bills often seek for classrooms to discuss "non-scientific alternatives" to evolution rather than out-rightly advocating the teaching of creationism.