Conversely, the youngest can be lazy, choosing to remain the baby and be taken care of. Adler describes a kind of paradox in which youngest children are both ambitious and lazy. He states that youngest children are often spoiled, and therefore cannot be independent. The youngest may be less achieving because he or she is indecisive and cannot choose which path to take or follow. In Adler’s words “sometimes a youngest child will not admit to any single ambition, but this is because he wishes to excel in everything, he wishes to be unlimited and unique” (Adler, 1958, p. 150).
The youngest child must be creative and flexible in order to forge his own position. Adler makes note of spacing in between siblings as an important factor in an individual’s personality development. The number of years that separates siblings from one another makes a difference in the profile they assume. Adler states “It is not only an actual oldest child that can behave like the oldest. The situation counts, not the mere order of birth” (Adler, 1958, p. 143).
For instance if there are two children born into a family in close proximity and then several years pass before the third and fourth child are born, it is likely that the third child will assume some of the features of the oldest. Furthermore, when there are several years separating siblings each child will have some of the features of an only child (Adler, 1958). These are basic birth order profiles as presented by Adler. He considers variables such as spacing when examining character traits based on a person’s ordinal position.
These differences are reflective of the family environment and how that family context is different for each child in a specific ordinal position. Sulloway’s Theory In his book Born to Rebel (1996), Frank J. Sulloway describes in detail his theory about how birth order and family dynamics affect an individual’s personality. His perspective is largely evolutionary and follows Darwinian principles. Sibling groups are of primary interest to Sulloway’s theory. He asserts that siblings are in competition for resources, specifically parental resources.
Children need the care of their parent(s), as humans are a species that is dependent in the early years of development. Survival is contingent upon the care of others in the formative years. Even after a person has reached a stage of development in which he or she can assume responsibility for their basic needs, parental attention is still important for continued social and emotional growth. Because of the competitive atmosphere within the sibling environment, diversity is important in order to vie for precious and limited resources. In Sulloway’s words “by pursuing disparate interests and abilities, siblings minimize direct competition” (p. 86)
Systematic differences in siblings within a family are a natural adaptation to increase the likelihood of receiving parental care and attention. Sulloway calls these differences “contrast effects” (p. 96). As he describes “Among siblings, dramatic differences are commonplace. They arise because siblings cultivate distinct niches within the family” (p. 95) A particular niche allows an individual his or her own space or area of expertise. A sense of individuality and distinctiveness comes from occupying a niche that is one’s own. With unique traits and skills each sibling has something to bargain with in competing for parental resources.
In Sulloway’s words, “Siblings are motivated to exploit unoccupied niches because they stand to gain something in the process: greater parental investment” (p. 97). For example if one child in a family excels in academics he or she has occupied that particular niche. The parents give that child attention and praise for their academic achievements. Another child in the same family will have to do something different to attract the attention of the parents. Rather than competing in the same arena of academics, this child may choose to pursue art or athletics to distinguish him or herself.
In accordance with the ideas of family niches and contrast effects, Sulloway has concluded that individuals in certain birth order positions exhibit particular traits adaptive to their ordinal position in the sibling group. Firstborn individuals have their choice of finding a niche. Typically they tend to conform to the ideals and standards of the parents, emulating the model presented by their adult caregivers. According to Sulloway “Given their special place within the family constellation, firstborns should be more amenable than laterborns to their parents’ wishes, values and standards” (p. 69).
Individuals in this position are likely to be most conventional and to conform to the status quo. Throughout most of childhood firstborn persons are physically larger and stronger and more cognitively advanced than their younger siblings. Because of this they may feel self-assured and confident of their superiority. In order to maintain their status “firstborns are likely to minimize the costs of having siblings by dominating them” (pp. 68-69). Additionally, Sulloway suggests that firstborns are more antagonistic and less agreeable than later born siblings in order to secure their position.
Some of the adjectives used to describe the firstborn sibling position are “dominant, aggressive, ambitious, jealous, and conservative” (p. 79). Because individuals born later into the family need to find their own niche, their personality traits tend to be noticeably different from that of their firstborn siblings. Sulloway purports “Relative to firstborns, laterborns are more nonconforming, adventurous, and unconventional” (p. 74). This would make sense as they move away from the already occupied niche of tradition and convention and seek to explore a new area in which to flourish.
In order to avoid competition and increase the opportunity to draw on precious parental resources, later born persons often rebel against the norm in an attempt to discover that which makes them unique. Sulloway notes a number of factors that influence birth order differences between siblings. Age gaps among siblings is one. Sulloway asserts that siblings roughly two to five years apart in age will be most competitive and are most likely to assume the aforementioned birth order traits. His reasoning is that if siblings are born in close proximity it is beneficial for one sibling to be altruistic to the other.
When two children are very close in age they have similar needs. Therefore, it is advantageous for siblings to work cooperatively to reap the benefits of shared parental resources. However when the age gap between siblings is greater than eighteen to twenty-four months the predicted patterns of competition and personality differences will emerge. For example, a child born three years before his or her siblings will tend to be the conscientious, conservative, dominant sibling while the younger will be more rebellious and open to experience.