Six Phases Described in Book

Clifford Grobstein’s book “Science & the Unborn” suggests that life in the womb can be separated into six fairly distinct phases:

* Genetic. The two-week “pre-embryo” phase, which begins at conception. The unborn develops its “hereditary uniqueness,” according to Grobstein. “It is essential to keep in mind how much is yet missing at this early stage.”

* Developmental. After about two weeks, the rapidly growing pre-embryo attaches to the uterine wall. From this point on, “it becomes committed to the production of a single individual.”

* Functional. After about two months, the embryo--now identified as a fetus--has developed certain abilities essential to survival. As the fetus develops, “it sets the stage for increasing functional individuality, including behavior.”

* Behavioral. This stage is difficult to describe because the unborn at different times exhibit various types of behavior, according to Grobstein. However, after about six or seven weeks, the development of

nerve and muscle tissue allows basic reflex responses. “Muscles and nervous system . . . (are) sufficiently mature . . . (as are) the interactions between them,” Grobstein says.

* Psychic. While this stage is open to debate, scientists believe that a “sense of self” probably doesn’t exist until about the 30th week, according to Grobstein. He defines psychic as an “inner subjective experience, such as each adult is directly aware of.”

* Social. “Social individuality” is not a biological phase, according to Grobstein. It is instead “conferred through recognition by others. . . . No matter how strong the experience of inner self may be, it has no social content unless it is recognized by another.”