Final answer:
The term Baltes & Baltes gave to the idea that workers deliberately try to keep crucial abilities sharp by taking additional training or periodically "brushing up" is selective optimization with compensation theory. This theory emphasizes personal development and the deliberate effort to maintain and enhance skills and abilities.
Step-by-step explanation:
The term Baltes & Baltes gave to the idea that workers deliberately try to keep crucial abilities sharp by taking additional training or periodically "brushing up" is selective optimization with compensation theory. This theory, based on personal development throughout the life course, emphasizes the components of selection, optimization, and compensation. It suggests that individuals can maintain and enhance their skills and abilities through deliberate effort and training.