Final answer:
Doug's developmental issues may stem from genetic predisposition and exposure to environmental teratogens during prenatal development.
Step-by-step explanation:
Genetic Predisposition: Doug may have an increased risk due to inherited genes that make him more susceptible to certain developmental issues.
Environmental Exposures: Exposure to teratogens, including certain drugs, alcohol, or environmental toxins during pregnancy, could have contributed to Doug's developmental challenges.