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816 22 MAY 2020 • VOL 368 ISSUE 6493 sciencemag.org SCIENCE
Of the roughly 530 undergraduates from
around the world who have attended MTBI
(see graphic, p. 815), more than 160 have
gone on to earn a Ph.D., he says—nearly
60% of whom are from groups historically
underrepresented in science. Those gradu-
ates represent roughly 40% of all Latino
Ph.D.s in math from U.S. universities in the
past decade, he says.
“Carlos Castillo-Chavez has been a gi-
ant in the field of STEM [science, technol-
ogy, engineering, and math] education
with respect to underrepresented minori-
ties over a period of almost 2 decades,” Ted
Greenwood, a former program officer at the
Alfred P. Sloan Foundation, which funded
MTBI for many years, wrote in a 60th birth-
day tribute to him.
MTBI’s reach extended far beyond ASU.
“Carlos began sending us alumni of his
MTBI program, most of them Latino,” re-
called Phil Kutzko, an emeritus professor
of math at the University of Iowa. “Without
his trust and support, it is unlikely that the
transformation of our graduate program ...
would have occurred,” Kutzko wrote in a re-
cent essay about the Math Alliance, which
he co-led for many years.
Carlos Torre, who earned his Ph.D. un-
der Castillo-Chavez in 2009 and has spent
the past decade on Wall Street, fell un-
der his spell as a Cornell undergraduate.
“It was the first time I had a professor
who looked and sounded like me,” recalls
Torre, who as an infant immigrated with
his family from Peru. “He had a very thick
accent, and a ponytail.”
Torre was intrigued when Castillo-Chavez
mentioned MTBI one day in class. He lob-
bied for a slot, and over the next several
years he received several doses of Castillo-
Chavez’s tough-love medicine.
“He called me out when I should have
been called out,” Torre says, recalling a
tongue-lashing he once received after drop-
ping a difficult graduate course that wasn’t
required for his degree. As punishment,
Castillo-Chavez barred Torre from doing his
own research that summer at MTBI.
Torre wasn’t happy, but he thinks
Castillo-Chavez was right. “It also meant a
lot to me that somebody cared so much.”
CASTILLO-CHAVEZ WAS RECRUITED to ASU by
Joaquin Bustoz, a beloved figure and former
chair of the math department who died in
a car crash before Castillo-Chavez arrived.
Castillo-Chavez immediately took over a
summer program for minority high school
students that Bustoz had run for almost
2 decades, adding it to the MTBI program as
part of his portfolio for increasing diversity.
The next step, he decided, was a
graduate program in applied math. But
Castillo-Chavez says he failed to win over his
colleagues in the math department.
“Carlos had created an enormous
amount of friction” in trying to obtain
more resources, recalls one longtime mem-
ber of the department, who requested ano-
nymity. “And the dean decided that could
not go on. So Carlos was given the oppor-
tunity to start his own program [in a dif-
ferent department]. There were not many
people in the department who regretted
seeing him leave.”
The result was the Levin center, located in
ASU’s School of Human Evolution and SocialChange. It serves as the administrative home
for AMLSS, a graduate program for apply-
ing math to model how social forces affect
the origin and spread of disease. Named to
honor Simon Levin, a prominent theoreti-
cal biologist and Castillo-Chavez’s mentor
at Cornell, the center doesn’t have its own
faculty. Instead, its work is carried out by vis-
iting scholars drawn from Castillo-Chavez’s
vast network of contacts.
Even as Castillo-Chavez’s empire grew
and accolades rolled in, so did conflicts with
colleagues and students. Former colleagues
say senior ASU officials either ignored re-
ports of questionable behavior or defended
him because his successful track record bur-
nished the university’s reputation.
Raskind says Castillo-Chavez maligned
him in emails to top ASU officials, in-
cluding Crow, and threatened to destroy
his career after Raskind put in a bid for
a deanship. (Raskind would later serve as
dean at two other research universities.)Raskind says his offense was saying no to
a request that his department provide com-
puting resources for the new center.
Senior officials ignored Raskind’s com-
plaints about Castillo-Chavez’s behavior,
he says, “and that’s when I knew it was
time to leave. I was a tenured professor, so
he couldn’t ruin my career. But he tried to
do similar things to some of his students,
which I think was disgraceful.”
Other former and current colleagues tell
similar stories. “Where it became toxic is
that, whenever you would get into a dis-
agreement with Carlos, he would make it
an issue about minorities,” says one ASU
faculty member. “He would send emails
to everybody at the university, insinuating
that you were a racist.”
One former student, who says he never
saw Castillo-Chavez act maliciously, thinks
professional jealousy may have been a fac-
tor in some of those clashes. “The fifth
floor [of one ASU building] was all Carlos,”
says Daniel Rios-Dorio, who joined AMLSS
in 2006 after participating in MTBI as a
graduating senior from the City Univer-
sity of New York. As many as 20 students
joined the program every fall, and each got
a laptop, plenty of space to work, and travel
funds to attend conferences. “The man was
clearly doing something right,” says Rios-
Dorio, who earned his Ph.D. in 2010.
AMLSS has no prescribed set of courses
and no qualifying exams. Castillo-Chavez
thought such requirements might penal-
ize students with weaker backgrounds and
believed a student’s research and publica-
tions were better metrics. But that flexibil-
ity also allowed Castillo-Chavez to make
random and arbitrary demands, such as
suddenly announcing that students must
attend a new course being offered by a vis-
iting colleague.
“He had different requirements for dif-
ferent students, and nobody knew what
any of those requirements were,” says Jack
Pringle, a second-year graduate student
in the program. “As soon as I arrived [in
2018], it was very clear that everyone was
terrified of Carlos. But there was also this
worship of Carlos. And I think he liked
having that power and dependency.”
Castillo-Chavez says such comments,
which he says he’s heard for years, mis-
characterize his approach to mentoring.
“I think that some students did not un-
derstand the rigors of the program, and
that its flexibility created challenges that
some students were unable to meet,” he
says. “I have devoted my life, and sacrificed
my family, to this cause. But if you want to
stand up and promote diversity and criti-
cize the lack of diversity [at an institution],
there will be people who accuse you of PHOTO: CAMELIA PHAM“I needed
somebody who would
believe in me.”
Maria Martinez,
Arizona State University, TempePublished by AAAS