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.
Sometimes fingernails develop harmless vertical ridges that run from the cuticle to the tip of the nail. Vertical ridges tend to become more prominent with age. Fingernails can also develop white lines or spots due to injury, but these eventually grow out with the nail. Not all nail conditions are normal, however.