ATTACHMENT INTODUCTION
ATTACHMENT SPECIFICATION
Caregiver-infant interactions in humans: reciprocity and interactional synchrony.
Stages of attachment identified by Schaffer.
Multiple attachments and the role of the father.
Animal studies of attachment: Lorenz and Harlow.
Explanations of attachment: learning theory
Explanations of attachment: Bowlby’s monotropic theory. The concepts of a critical period and an internal working model.
Ainsworth’s ‘Strange Situation’. Types of attachment: secure, insecure-avoidant and insecure-resistant.
Cultural variations in attachment, including van Ijzendoorn.
Bowlby’s theory of maternal deprivation.
Romanian orphan studies: effects of institutionalisation.
The influence of early attachment on childhood and adult relationships, including the role of an internal working model
WHAT IS ATTACHMENT?
Love and attachment have long been considered fundamental aspects of human experience, but their origins can be understood through an evolutionary lens. Attachment theory, a psychological, evolutionary, and ethological perspective, suggests that strong emotional bonds are essential for survival. Infants require at least one primary caregiver to develop normally, and this need for attachment extends beyond childhood into adult romantic relationships. The evolutionary explanation for why humans fall in love is rooted in reproduction. Species can only continue through reproduction, and evolutionary success depends on ensuring offspring survive to adulthood. Romantic love, therefore, is not an accident of human emotion but a mechanism designed to encourage mating and long-term pair bonding. Without emotional attachment, humans would be less likely to form relationships, reproduce, and raise children successfully.
Unlike species where females can rear offspring independently, humans require cooperative parenting. In ancestral environments, pregnant or nursing women faced significant vulnerabilities—they needed protection from predators and rival groups and assistance in obtaining food. A bonded mate provides stability and resources, increasing the survival chances of both the mother and child. The extended dependency of human infants further reinforces the need for long-term pair bonding, as children take years to develop the necessary skills for survival.
This evolutionary drive for attachment is not limited to romantic relationships but extends to parental bonds. Species tend to attach to their offspring when parental care is essential for survival. For instance, fish and reptiles, whose young are self-sufficient from birth, display little to no parental attachment. In contrast, mammals—and particularly humans—invest heavily in their offspring because their survival depends on prolonged caregiving.
The biological foundation of love and attachment lies in neurochemistry. Hormones such as dopamine, oxytocin, and vasopressin play a crucial role in reinforcing emotional bonds. Dopamine is associated with pleasure and reward, creating feelings of euphoria when individuals are with their partners or children. Oxytocin, often called the "bonding hormone," strengthens attachment and is released during childbirth, breastfeeding, and physical affection. Vasopressin supports long-term commitment by fostering social recognition and attachment. These chemical processes ensure that humans not only seek out romantic partners but also maintain strong parental and social bonds that contribute to group cohesion and survival.
Ultimately, love and attachment are not arbitrary emotions but carefully honed evolutionary mechanisms that have allowed humans to thrive. Whether in romantic relationships, parent-child bonds, or close social connections, these attachments ensure the continuation of the species by promoting cooperation, caregiving, and the long-term investment needed to raise vulnerable offspring.
PRECOCIAL AND ALTRICIAL SPECIES
The terms precocial and altricial are used in ethology, the biological study of animal behaviour, to describe the developmental state of offspring at birth or hatching. These classifications help explain differences in parental investment, survival strategies, and cognitive development across species.
While precocial and altricial are the two primary classifications of offspring development, they exist on a continuum rather than as rigid categories. Some species do not fit neatly into either group and instead display characteristics that fall somewhere in between.
SEMI-PRECOCIAL AND SEMI-ALTRICIAL SPECIES
Some animals exhibit a mix of precocial and altricial traits, leading to semi-precocial and semi-altricial species classifications.
Semi-precocial species: These animals are relatively mature at birth but still require significant parental care. For example, gulls and penguins hatch with open eyes and downy feathers but depend on their parents for food and protection.
Semi-altricial species: These species are born helpless like altricial animals but develop more rapidly and may begin moving or feeding earlier. Owls, hawks, and some marsupials fall into this category—they are born immature but remain in the nest under parental care while developing.
SUPERNORMAL SPECIES
Some species, particularly insects and amphibians, produce vast offspring with minimal to no parental investment. Many of these young die before reaching maturity, but their survival strategy relies on sheer numbers rather than parental care. Frogs, sea turtles, and many fish species lay hundreds or thousands of eggs, with only a tiny fraction surviving to adulthood.
PRECOCIAL SPECIES
Precocial species are relatively mature, mobile, and independent soon after birth or hatching. Their brains are well-developed at birth, relying heavily on instinct rather than learning. However, because their brains do not develop much beyond birth, they cannot adapt and memorise extensively as they grow.
Key Characteristics:
Born or hatched with open eyes, fur/feathers, and the ability to move.
Require less parental care than altricial species.
Rely on innate behaviours rather than learning from experience.
Tend longer gestation or incubation periods to allow for greater prenatal development.
Examples of Precocial Species:
Birds: Ducks, chickens, geese – hatchlings can immediately walk and follow their mother.
Mammals: Horses, deer, giraffes – newborns can stand and walk within hours.
Reptiles: Many reptiles, such as turtles and crocodiles, hatch fully functional and independent.
ALTRICIAL SPECIES
Altricial species are animals born undeveloped and require significant care, feeding, and protection from their parents. Unlike precocial species, their brains are less developed at birth but continue to grow and develop, allowing them to learn, adapt, and develop complex skills over time.
Key Characteristics:
Born helpless, blind, and immobile, often lacking fur or feathers.
Depend on parental care for food, warmth, and protection.
Their brains develop after birth, allowing for more significant learning, adaptation, and problem-solving.
They tend to have shorter gestation or incubation periods since their development occurs postnatally.
Examples of Altricial Species:
Birds: Owls, pigeons, songbirds – hatchlings are blind, featherless, and require feeding.
Mammals: Humans, dogs, cats, rodents – newborns rely on their parents for survival and learning.
COMPARISON & HUMAN DEVELOPMENT
Humans are an extreme example of an altricial species, born in an underdeveloped state but with tremendous cognitive potential. Unlike precocial species, which rely on instinct, humans have an extended period of brain development, allowing for greater learning, problem-solving, and social interaction. This prolonged childhood dependency is one of the key factors behind human intelligence, adaptability, and culture.
COMPLEX ANIMALS VERSUS NON-COMPLEX ANIMALS
The more complex an organism, the longer it takes to develop. Life evolved over billions of years, from single-celled microorganisms to large-brained mammals, with mammalian parental care becoming increasingly complex. Mammals invest heavily in their young, as survival depends on learning essential skills rather than relying solely on instinct. A key feature of mammalian care is maternal nursing, where mothers provide milk for their offspring.
WHAT SPECIES HAS THE LONGEST CHILDHOOD?
Orangutans have one of the longest childhoods in the animal kingdom. While orangutans in captivity can reproduce as early as six years old, they remain dependent on their mothers for far longer in the wild. Infant orangutans are nursed for around six years, and even after weaning, they stay close to their mothers, learning survival skills.
Like humans, female orangutans form strong, lasting bonds with their offspring.
For the first two years, orangutan infants depend entirely on their mothers, clinging to them as they navigate the jungle.
Some orangutan mothers allow their offspring to stay for three years after weaning, while others encourage independence sooner.
WHAT ANIMALS STAY WITH THEIR MOTHERS FOR LIFE?
Certain species form lifelong bonds with their mothers, while others have extended parental care due to the complexity of their social structures and survival needs.
African Elephants – Have the longest gestation period of any mammal (22 months). Calves nurse for four to six years and remain with their mothers for up to 16 years. Female elephants stay in the herd for life.
Chimpanzees – Mothers provide care and protection for years, with young chimps learning essential skills for survival.
Dolphins – Calves stay with their mothers for several years, forming strong social bonds within their pods.
Lions – Cubs remain with their mothers for up to two years, learning to hunt and navigate the pride’s hierarchy.
Grey Kangaroos – Joeys stay in their mother’s pouch for about nine months and continue to suckle for over a year.
Alligators – Unlike most reptiles, female alligators provide parental care, guarding their young for up to a year.
Giraffes, Gazelles – While not as long as some species, young animals remain close to their mothers, learning survival strategies.
PARENTAL CARE IN THE ANIMAL KINGDOM
Parental care varies widely across species, depending on evolutionary pressures, reproductive strategies, and environmental demands. Some species provide no care, while others invest heavily in raising their offspring.
NO PARENTAL CARE
Parental care is uncommon among invertebrates and many fish species, where reproduction is based on quantity rather than quality. In these cases, parents produce many offspring but do not invest in survival.
Invertebrates – Many species lay eggs and abandon them without further involvement in offspring survival.
Most Fish – Gametes are released into the water, and offspring develop independently without parental support.
Reptiles – Many species, including most lizards and snakes, lay eggs and leave them to hatch. However, some exceptions exist:
Crocodilians – Mothers protect their nests and assist hatchlings in reaching water, sometimes staying with them for several months.
Tilapia (Fish) – Practise oral brooding, where the mother carries eggs in her mouth until they hatch, providing extra protection and nutrients.
BIPARENTAL CARE
Biparental care occurs when both male and female parents cooperate to raise their offspring. Although relatively rare, this behaviour has evolved in birds, mammals, amphibians, and some fish and insects.
Monogamous species are more likely to exhibit biparental care, as both parents benefit from ensuring their offspring survive.
Polygamous species (where one male mates with multiple females) often see female-only care, as males invest less due to paternity uncertainty.
Promiscuous species (where multiple males and females mate freely) typically have little to no male parental involvement, as ensuring genetic relatedness is difficult.
PARENTAL CARE IN BIRDS
Birds are unique among vertebrates for their high levels of biparental care. Around 90% of bird species exhibit cooperative parenting, with both parents sharing responsibilities such as feeding, protecting, and incubating eggs.
Alloparental care (Helpers at the nest) – In some species, non-parental individuals assist in raising offspring, often younger siblings from previous broods.
Female-only care is still standard in certain bird species, while male-only care is rare but exists in a few species, such as emus and seahorses.
CONCLUSION
Evolutionary trade-offs between offspring survival and reproductive opportunities shape parental investment. Species with high parental care tend to have fewer offspring but provide more significant investment in each, while those with no parental care produce large numbers of offspring with low survival rates. Birds, mammals, and some reptiles and fish have evolved varied parenting strategies, demonstrating the complexity of reproductive behaviour across the animal kingdom.
The length of childhood dependency varies significantly between species and is largely influenced by the complexity of the animal’s cognitive and social needs. In humans, as in orangutans and elephants, prolonged parental care allows for advanced learning, adaptation, and the development of intricate social structures, setting them apart from species that rely on instinct alone.
PARENTAL CARE IN THE ANIMAL KINGDOM
Parental care varies widely across species and is influenced by evolutionary pressures, mating systems, and survival strategies. While some species provide no care, others invest heavily in rearing their young.
NO PARENTAL CARE
Parental care is rare in invertebrates and many fish species, where reproduction prioritises quantity over quality. These species produce large numbers of offspring but provide no direct care.
Invertebrates – Most lay eggs and abandon them, leaving offspring to survive independently.
Most Fish – Gametes are released into the water, and offspring develop without parental support.
Reptiles – Many species, including most lizards and snakes, lay eggs and leave them to hatch.
Crocodilians – Exceptionally, female crocodiles guard their nests and transport hatchlings to water, sometimes staying with them for months.
Tilapia (Fish) – Practise oral brooding, where the mother carries eggs in her mouth until they hatch, offering protection and nutrients.
BIPARENTAL CARE
Biparental care occurs when both male and female parents cooperate to raise offspring. Although uncommon, it has evolved in birds, mammals, amphibians, fish, and insects.
Monogamous species are more likely to exhibit biparental care, ensuring offspring survival.
Polygynous species (where one male mates with multiple females) often see female-only care, as males invest less due to paternity uncertainty.
Promiscuous species typically involve little or no male parental involvement, as fathers cannot confirm genetic relatedness.
PARENTAL CARE IN BIRDS
Birds are unique among vertebrates for their high levels of biparental care. Around 90% of bird species exhibit shared parenting, including feeding, incubating eggs, and protecting young.
Alloparental care (Helpers at the nest) – Some species, such as meerkats and certain birds, have non-parental individuals assisting in rearing offspring.
Female-only care is standard in some bird species, while male-only care is rare but seen in emus and seahorses.
SINGLE-PARENT CARE: MALES
Male parental care is rare but evolves when the benefits of caring outweigh the costs of seeking additional mates.
Birds: Found in 1% of bird species, such as emus and jacanas, where males exclusively incubate eggs and raise chicks.
Fish & Amphibians: Some species show male-only care, such as:
Giant water bugs – Males carry eggs on their backs until they hatch.
Seahorses – Males are unique in becoming pregnant and giving birth. However, they provide no care after birth.
SINGLE-PARENT CARE: FEMALES
Female-only care is the most common form of parental investment, particularly in mammals, where 95% of species rely solely on the mother for care.
Mammals: Almost all species rely on maternal care, as only females produce milk.
Exceptions: Some mammals, such as wolves and lions, show shared parenting within social groups.
BAD PARENTING IN THE ANIMAL KINGDOM
While parental care is essential for many species, some animals abandon or neglect their offspring in favour of survival or reproductive success.
Harp Seals – Mothers nurse pups for 12 days before leaving them alone.
Rabbits – Avoid their young to prevent attracting predators.
Pandas – Typically give birth to twins but abandon the weaker ones.
Hooded Grebes – Leave unhatched eggs if another chick has already hatched.
CONCLUSION
Parental care strategies vary widely across species, shaped by evolutionary trade-offs between offspring survival and reproductive opportunities. While mammals and birds invest heavily in their young, many fish and reptiles rely on sheer numbers for species survival. Understanding these strategies highlights the diverse ways in which species ensure their genes are passed on.
