What research method is used in order to establish what causes a behavior? an experiment What is the first step of the scientific method? pose a question In the science of human development, &quot;nurture&quot; refers to: environmental influences.
Vertical lines on one's nails, like those the writer seems to have, are a common phenomenon that often get more pronounced with age. There are many reasons for ridged nails but the most common is aging, says Dr. Phoebe Rich, M.D., FAAD, clinical adjunct professor of dermatology at Oregon Health Science University.
Another main cause of lip lines is thinning skin. As you age, your skin tends to become thinner and more likely to become creased with use. All facial lines, including lip lines, are more visible as skin becomes thinner. Aside from giving up smoking, it sounds like there's little you can do to avoid lip lines.