Dennis earned his doctoral degree at the University of Illinois-Urbana. He has taught art, English, history and geography in K-12 public and private schools. He was tenured faculty at both the University of Houston and Texas Tech University. He has published three books on education, and lectured, researched, and/or taught in 19 countries. He was named Texas Art Educator of the Year in 1999, and Art Teacher of the Year for the Western U.S. in 2000. He is a registered advisor on arts education with the U.S. Department of Education.
He and his wife Mary have six children and nine grandchildren (all of whom are above average and advanced for their ages).
Dennis is listed with the Texas Organ Donor Registry and is a 4-gallon blood donor. He has volunteered with Meals on Wheels, the Houston Oasis, and the Houston Food Bank. He enjoys time with family and friends, traveling the world, and spending hours and hours in his art studio.