Developmental psychology explores how our behaviors and thoughts change throughout... Show more
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Knowunity AI
Subjects
Triangle Congruence and Similarity Theorems
Triangle Properties and Classification
Linear Equations and Graphs
Geometric Angle Relationships
Trigonometric Functions and Identities
Equation Solving Techniques
Circle Geometry Fundamentals
Division Operations and Methods
Basic Differentiation Rules
Exponent and Logarithm Properties
Show all topics
Human Organ Systems
Reproductive Cell Cycles
Biological Sciences Subdisciplines
Cellular Energy Metabolism
Autotrophic Energy Processes
Inheritance Patterns and Principles
Biomolecular Structure and Organization
Cell Cycle and Division Mechanics
Cellular Organization and Development
Biological Structural Organization
Show all topics
Chemical Sciences and Applications
Atomic Structure and Composition
Molecular Electron Structure Representation
Atomic Electron Behavior
Matter Properties and Water
Mole Concept and Calculations
Gas Laws and Behavior
Periodic Table Organization
Chemical Thermodynamics Fundamentals
Chemical Bond Types and Properties
Show all topics
European Renaissance and Enlightenment
European Cultural Movements 800-1920
American Revolution Era 1763-1797
American Civil War 1861-1865
Global Imperial Systems
Mongol and Chinese Dynasties
U.S. Presidents and World Leaders
Historical Sources and Documentation
World Wars Era and Impact
World Religious Systems
Show all topics
Classic and Contemporary Novels
Literary Character Analysis
Rhetorical Theory and Practice
Classic Literary Narratives
Reading Analysis and Interpretation
Narrative Structure and Techniques
English Language Components
Influential English-Language Authors
Basic Sentence Structure
Narrative Voice and Perspective
Show all topics
187
•
Updated Feb 25, 2026
•
Developmental psychology explores how our behaviors and thoughts change throughout... Show more





Our journey begins before birth, with genetics playing a crucial role. A zygote (fertilized egg) develops into an embryo and later a fetus that can respond to sound by six months. During the critical period, harmful substances called teratogens can damage the developing baby if the mother ingests them.
Newborns come equipped with several reflexes - involuntary reactions like sucking, swallowing, and the rooting reflex (turning their head when touched on the cheek). Their senses are developing at different rates - they can hear before birth but are born with underdeveloped vision (essentially "legally blind").
Motor development follows a predictable pattern as babies learn to roll over around 5½ months, stand at 8-9 months, and walk independently by 15 months. This development occurs through maturation - biological growth processes that happen naturally with minimal influence from experience.
💡 Quick Fact: Attachment, the emotional bond between infant and caregiver, is so important that babies often prefer contact comfort (touching something soft) over food when stressed, as shown in Harry Harlow's famous monkey experiments!

Researchers like Harry Harlow and Mary Ainsworth revolutionized our understanding of attachment. Harlow's famous monkey studies showed that baby monkeys preferred soft surrogate "mothers" over wire ones that provided food, demonstrating the importance of contact comfort. Ainsworth identified three attachment patterns through the "strange situation" test:
Most babies show secure attachment - they're confident when parents are present and seek comfort when they return after an absence. Others display avoidant attachment (resist being held, don't seek comfort) or anxious/ambivalent attachment (show distress when alone but resist comfort when parents return).
Psychologist Diana Baumrind identified three distinct parenting styles that affect development. Authoritarian parents enforce strict rules with punishment, while permissive parents provide few consistent guidelines. The most effective approach is the authoritative style, where parents set reasonable standards with explanations and balance praise with discipline.
🧠 Think About It: Your attachment style and your parents' approach to discipline likely shaped your own comfort with relationships and authority. Can you identify which patterns you experienced growing up?

Sigmund Freud proposed that personality develops through psychosexual stages, where conflicts can cause fixation at particular stages. These include the oral stage , anal stage (1-3), phallic stage (3-5), latency period , and genital stage (puberty onward). Each stage focuses on different body areas as sources of pleasure and psychological development.
Erik Erikson expanded on Freud's work with his psychosocial stage theory, focusing on how social interactions shape identity. Each stage presents a specific challenge, from trust vs. mistrust in infancy to integrity vs. despair in old age. Successfully resolving each stage's conflict builds psychological strength for future challenges.
Jean Piaget revolutionized our understanding of children's thinking with his four stages of cognitive development. He discovered that children of similar ages often make similar "mistakes" in reasoning. His stages include the sensorimotor stage , preoperational stage , concrete operational stage (8-12, developing logical thinking and understanding conservation), and formal operational stage .
👉 Remember: Piaget's theory has been criticized for underestimating children's abilities - many children progress through these stages faster than he predicted!

Lawrence Kohlberg proposed that moral reasoning develops through three distinct levels. The pre-conventional level focuses on avoiding punishment and gaining rewards. The conventional level emphasizes following social rules and norms. Finally, the post-conventional level involves understanding universal ethical principles beyond specific rules.
Kohlberg's theory faced criticism for not adequately sampling females in his research. Carol Gilligan addressed this gap by studying girls' responses to moral dilemmas like the "Heinz question" (whether a man should steal medicine for his dying wife). She found that girls typically scored lower on Kohlberg's scale but suggested this wasn't due to less developed morality.
Gilligan argued that girls tend to consider situational factors and relationships more carefully, while boys often use more absolute moral judgments. This gender difference highlights how moral reasoning can vary based on different priorities and perspectives.
🔍 Important Insight: The development of morality isn't just about learning rules - it reflects deeper cognitive development, social understanding, and even gender differences in how we approach ethical problems.
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
App Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
Developmental psychology explores how our behaviors and thoughts change throughout life, from conception to death. This fascinating field examines key debates like nature vs. nurture and whether development occurs continuously or in distinct stages. Understanding how we develop helps explain... Show more

Access to all documents
Improve your grades
Join milions of students
Our journey begins before birth, with genetics playing a crucial role. A zygote (fertilized egg) develops into an embryo and later a fetus that can respond to sound by six months. During the critical period, harmful substances called teratogens can damage the developing baby if the mother ingests them.
Newborns come equipped with several reflexes - involuntary reactions like sucking, swallowing, and the rooting reflex (turning their head when touched on the cheek). Their senses are developing at different rates - they can hear before birth but are born with underdeveloped vision (essentially "legally blind").
Motor development follows a predictable pattern as babies learn to roll over around 5½ months, stand at 8-9 months, and walk independently by 15 months. This development occurs through maturation - biological growth processes that happen naturally with minimal influence from experience.
💡 Quick Fact: Attachment, the emotional bond between infant and caregiver, is so important that babies often prefer contact comfort (touching something soft) over food when stressed, as shown in Harry Harlow's famous monkey experiments!

Access to all documents
Improve your grades
Join milions of students
Researchers like Harry Harlow and Mary Ainsworth revolutionized our understanding of attachment. Harlow's famous monkey studies showed that baby monkeys preferred soft surrogate "mothers" over wire ones that provided food, demonstrating the importance of contact comfort. Ainsworth identified three attachment patterns through the "strange situation" test:
Most babies show secure attachment - they're confident when parents are present and seek comfort when they return after an absence. Others display avoidant attachment (resist being held, don't seek comfort) or anxious/ambivalent attachment (show distress when alone but resist comfort when parents return).
Psychologist Diana Baumrind identified three distinct parenting styles that affect development. Authoritarian parents enforce strict rules with punishment, while permissive parents provide few consistent guidelines. The most effective approach is the authoritative style, where parents set reasonable standards with explanations and balance praise with discipline.
🧠 Think About It: Your attachment style and your parents' approach to discipline likely shaped your own comfort with relationships and authority. Can you identify which patterns you experienced growing up?

Access to all documents
Improve your grades
Join milions of students
Sigmund Freud proposed that personality develops through psychosexual stages, where conflicts can cause fixation at particular stages. These include the oral stage , anal stage (1-3), phallic stage (3-5), latency period , and genital stage (puberty onward). Each stage focuses on different body areas as sources of pleasure and psychological development.
Erik Erikson expanded on Freud's work with his psychosocial stage theory, focusing on how social interactions shape identity. Each stage presents a specific challenge, from trust vs. mistrust in infancy to integrity vs. despair in old age. Successfully resolving each stage's conflict builds psychological strength for future challenges.
Jean Piaget revolutionized our understanding of children's thinking with his four stages of cognitive development. He discovered that children of similar ages often make similar "mistakes" in reasoning. His stages include the sensorimotor stage , preoperational stage , concrete operational stage (8-12, developing logical thinking and understanding conservation), and formal operational stage .
👉 Remember: Piaget's theory has been criticized for underestimating children's abilities - many children progress through these stages faster than he predicted!

Access to all documents
Improve your grades
Join milions of students
Lawrence Kohlberg proposed that moral reasoning develops through three distinct levels. The pre-conventional level focuses on avoiding punishment and gaining rewards. The conventional level emphasizes following social rules and norms. Finally, the post-conventional level involves understanding universal ethical principles beyond specific rules.
Kohlberg's theory faced criticism for not adequately sampling females in his research. Carol Gilligan addressed this gap by studying girls' responses to moral dilemmas like the "Heinz question" (whether a man should steal medicine for his dying wife). She found that girls typically scored lower on Kohlberg's scale but suggested this wasn't due to less developed morality.
Gilligan argued that girls tend to consider situational factors and relationships more carefully, while boys often use more absolute moral judgments. This gender difference highlights how moral reasoning can vary based on different priorities and perspectives.
🔍 Important Insight: The development of morality isn't just about learning rules - it reflects deeper cognitive development, social understanding, and even gender differences in how we approach ethical problems.
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
8
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Practice Test ✓ Essay Outlines
This know covers everything you may need to know about Jean Piaget & his theory of Cognitive development, as well as explanations of each step of cognitive development
Need to know terms for developmental psychology.
Explore Lawrence Kohlberg's theory of moral development, detailing the pre-conventional, conventional, and post-conventional stages. This summary covers the aim, methodology, and key findings from his longitudinal study on moral reasoning in children and adolescents, highlighting the evolution of ethical principles across different cultural contexts.
Study notes covering AP Psych curriculum
This is a summary I made for the 4 communication skills: Reading, writing, listening and speaking.
Explore the intricate relationship between Theory of Mind (ToM), social cognition, and autism spectrum disorder (ASD). This summary covers key concepts such as Selman's stages of social development, the role of mirror neurons in empathy, and the implications of ToM deficits in individuals with ASD. Ideal for psychology students seeking to understand cognitive development and social interactions.
App Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user