The worldwide bestseller and multiple award winning The Wonder Weeks describes the incredible mental developmental changes (leaps) and regression periods that all babies go through. Based on the scientific — and parental — world-changing discovery of a phenomenon: all healthy babies appear to be more fussy at very nearly the same ages, regression periods, and sleep less in these phases. These age-related fluctuations in need for body contact and attention (regression periods) are related to major and quite dramatic changes in the brains of the children. These changes enable a baby to enter a whole new perceptual world and, as a consequence, to learn many new skills. Understanding the real reason behind crying, eating, and sleeping problems is the only real solution every parent needs.