Biology Now, 2e

A Critical Choice ■ 25

Eaton didn’t know the source of the original

claim that vaccines cause autism, but she knew

that in order to be scientifically literate and

make an informed decision for her daughter, she

needed to find it. Scientific claims directly affect

our lives because we make decisions based on

them. Some of these are small decisions: Should

I take a multivitamin every morning? How often

should I exercise?

Others are larger decisions: Should I vote to

support carbon taxes? Does a cell phone cause

tumors from radiation? Should I vaccinate my

children? The good news is that you can learn to

evaluate scientific claims. You can be skeptical

about claims and, using critical thinking, make

scientifically literate decisions for yourself.

Credentials, Please

Caroline was born in January 2010 (Figure 2.4).

Eaton had Caroline vaccinated when she was two

months old, but then Eaton found herself gripped

with fear. “I worried I was doing more harm than

good,” she says. Because of her rising fears, she

did not get Caroline’s four-month vaccinations.

Eaton sought out a pediatrician who would

discuss her fears about vaccination. Several

pediatricians refused to talk with her about a

delayed vaccination schedule; some even refused

to treat Caroline if she was not vaccinated.

Finally, Eaton found a pediatrician who was

willing to listen and discuss. After Eaton shared

her concerns about vaccine safety, the pediatri-

cian handed Eaton a book, Vaccines and Your

Child, by a pediatrician named Paul Offit. In the

book, Offit laid out how vaccines work, how they

are made, and which risks are real and which

are false. He also provided documentation, with

detailed references to scientific papers, showing

that there is no scientific evidence that vaccines

cause autism.

Eaton found the book to be well written and

informative, but she wondered whether she could

trust Offit. She checked his credentials—a first

step toward assessing the strength of a person’s

scientific claim. Does the person making a scien-

tific claim have a PhD or MD? Is the degree in

the field in which they are making the claim?

PhDs in physics do not have training in germ

theory, for example, and medical doctors do not

have training in atmospheric science.

Offit had an MD from the University of Mary-

land and was a professor of vaccinology and pedi-

atrics at the University of Pennsylvania. He was

also chief of the Division of Infectious Diseases

and the director of the Vaccine Education Center

at the Children’s Hospital of Philadelphia. In

other words, Offit had an advanced degree in an

appropriate field and held a job at a reputable

university. While good credentials alone do not

guarantee that a source is trustworthy, scientists

practice for many years in their area of expertise,

and their scientific claims tend to be based on

that expertise and carefully stated.

In addition to evaluating someone’s creden-

tials, it is important to assess whether the person

making a scientific claim has an agenda or bias

(a prejudice or opinion for or against something).

Does the person have an ideological, political, or

religious belief that will be supported by the scien-

tific claims being made? Does the person have a

Figure 2.4

Anna and Caroline Eaton

Anna Eaton had concerns about vaccinations for

her first child, Caroline.

Paul Offit is a pediatrician and chief of the Division

of Infectious Diseases at the Children’s Hospital

of Philadelphia.

PAUL OFFIT