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.
There are a number of potential causes for ridges on fingernails. Vertical ridges which run the length of the nail are actually quite common, especially among older people, although they can be a cause for concern, especially when paired with color changes in the nail. Horizontal ridges are often an indicator of a health problem which requires medical attention.