1. Trust Vs Mistrust (0-1)
This stage looks at babies' ability to trust their parents to look after their needs for warmth, food, and affection. If needs are consistently met, they will be able to trust themselves, their environment, and others as well as develop healthy attachments to others.
The show doesn't show Meredith at this stage, but it appears that her father primarily takes care of her and as a child this stage was passed, though later events cause Meredith to have to face this crisis once again.
2. Independence Vs Doubt (1-2)
Toddlers are learning new skills, like walking, talking, and using the toilet. These things allow elf control and self confidence to develop. The reaction of their caregivers to any mistakes helps build confidence or creates shame.
Again, the show mentions Meredith very little at this age and it is assumed that she passes, as she decides that she wants to pursue something that is difficult and requires a lot of skill. Her father is still her primary source of love and affection, and he appears to be supportive as well as giving her whatever she wants.
3. Initiative Vs Guilt (2-6)
Children have developed motor skills and are active in social environments. They must learn to achieve a balance between responsibility and adventure. They must learn to control impulses and learn the difference between reality and fantasy.
Meredith is forced to pass this stage as her mother takes her across the country, but remains a career driven surgeon. Meredith begins to fend for herself, going so far as to save her mother's life when her mother slits her own wrists. This is the stage where Meredith's development happens too quickly as she has no real source of care. While she is able to tell the difference between reality and fantasy, it is difficult to tell if she truly learns to control her impulses.
4. Competence Vs Inferiority (6-12)
Children go to school. They make the transition from world of home to world of their peers and learn skills to become a future provider. These skills include using tools and making things. If children are able to find pleasure in being productive and seeking success, then they will develop competence rather than a sense of inferiority.
Meredith appears to enjoy school, though she doesn't agree with everything that her teachers try to teach her over the years. She continues to seek success in her life, which implies that she did pass that part of the stage. She does seem to have some lasting issues of inferiority into Young Adulthood, indicating that she didn't entirely pass this stage.
5. Identity Vs Role Confusion (12-18)
All earlier conflicts must be resolved in order for the adolescent to know who they are and to resolve their identity crisis. Solving the identity crisis allows the individual to have a strong sense of self and the ability to plan for the future. If the identity crisis isn't solved, the adolescent will be confused about important life decisions such as sexuality, vocation, and general life.
Meredith appears to pass this stage as well. She has some issues due to the neglect of her mother and the absence of her father. Despite these issues, she realizes she has a calling as a surgeon and goes to medical school against her mother's advice. There are some issues that Meredith does leave unresolved however and this contributes to some of her issues in Young Adulthood.
6. Intimacy Vs Isolation (19-40)
Erikson says that no matter how successful you are in your work, you will not be truly complete until you have intimacy. Men must develop identity before they can develop intimacy, where women develop identity through intimacy. Without identity, most will fear committed relationships.
Meredith struggles to find her identity, especially in regards to intimacy, but she does eventually develop both as well as find professional success. She has many reservations about intimate relationships on both romantic and platonic levels and serious reservations about having children as she believes that she will be a terrible mother.