Why Are We All So Anxious?

Barbara Heffernan • May 14, 2025

The Evolutionary Mismatch That Creates Anxiety

Why are we ALL SO ANXIOUS so much of the time? 

Understanding the evolutionary root of our anxiety can be tremendously helpful in figuring out how to recover and what we can do differently. This knowledge helps us feel less defective when we understand that our brains evolved in a very different environment than we live in now, and that this mismatch causes much of our anxiety.

The Delayed Return Environment and Anxiety

Anthropologists use two particularly interesting and useful terms to describe this phenomenon. One is a "delayed return environment," which is what we live in now. The other is an "immediate return environment," which the earliest humans lived in, as did most creatures prior to human beings. Let me explain how this connects to anxiety and why it matters to you.

Consider an antelope living on a savannah. That antelope lives in an immediate return environment, which means that if it sees lions approaching, it runs immediately. This represents an immediate response to an immediate threat. When that lion is prowling and beginning to attack, the antelope has no other thought but to run as fast as possible. Then, when there are no threats, that antelope eats grass or drinks water, again getting an immediate return from its behavior.

For us humans, most of our problems lie in the future. There are delayed consequences to the actions we take today. In order to eat, we don't simply head to our lawns and munch on grass. We have to plan, maintain a job, receive a paycheck, go to the store, and prepare food.

Our brains evolved in an immediate return environment, with a focus on survival above all. This means that if there is any kind of threat or danger, our amygdala fires super fast.

When faced with immediate danger, like a lion attacking, we want that amygdala to take over. The amygdala makes us fight, flee, or freeze.

But as we've discussed in this blog and on my YouTube channel, most threats we face today are NOT immediate.

We might perceive them to be life-threatening in the long term, but our bodies are having all the chemical reactions of an immediate threat.

Our Neocortex: Blessing and Curse

A significant difference between us and that antelope is that we have a more developed neocortex. Our neocortex is extremely useful in many ways. Without it, we couldn't live in a delayed return environment.

In fact, it is only because we have a neocortex that we have been able to develop this delayed return environment in the first place.

The neocortex is the part of our brain that handles planning, projects into the future, helps us delay gratification, and assists with problem-solving.

You might have already heard that animals living in an immediate return environment don't tend to have anxiety disorders because they run and release their stress in the moment when it's appropriate. But there's another critical element: the antelope cannot predict the future.

After reaching safety and beginning to eat grass, the antelope doesn't think, "Oh no, those lions will return tomorrow. How do I prevent that? I can't prevent that," and become increasingly anxious.

It is our ability to predict the future that creates our anxiety. It's a combination of living in a delayed return environment and having this amazing predictive machine in our brain that can work too hard, developing all sorts of catastrophic stories. Since different parts of our brain don't communicate perfectly with each other, the part predicting the story doesn't realize that older parts of our brain believe that story, generating the same stress chemicals. We then get caught in a cycle of catastrophic predictions, anxiety, worry, and chemical reactions that continues until we learn how to stop it.

**[Our Evolutionary Timeline](#)**

To put this in perspective:
- Reptiles evolved over 300 million years ago
- Mammals evolved over 200 million years ago
- Homo sapiens evolved 300,000 years ago
- Humans have been living in a delayed return environment for about 500 years

That 500 years represents approximately 0.17% of the time that human beings as we know them today have existed. In evolutionary terms, it's an extraordinarily small amount of time, and our brains haven't changed enough to fully adapt. However, there are things you can do to change your own brain to make this adaptation easier.

**[How Our Brain Creates Anxiety](#)**

Our ability to predict the future is beneficial if we don't get completely lost in the story. When we do get lost in the story, we generate all the chemicals associated with that scenario. We might cry if we're thinking about something sad, or experience stress chemicals when thinking about anything stressful—even though it isn't actually happening.

This is why bringing your attention into the present moment and trying to absorb what's around you right now can help calm overactive anxiety. I'll follow this article with two more that break this down further: one focusing on catastrophizing (going to the worst-case scenario), and the other on the physical chemicals generated during anxiety.

There are other factors that contribute to anxiety:

1. **Survival Prioritization**: Our brain evolved to keep us safe, with survival as the number one priority. That's why the amygdala is so powerful and can override other brain functions.

2. **Conditioned Fear Responses**: As we go through life, we condition our brain to have fear responses in various situations. If something frightening happens to you as a child, you likely embedded a memory—perhaps a smell, sight, or sound—with a fear reaction deep in your subconscious mind.

3. **Avoidance Reinforcement**: When we fear something, we often avoid it. This avoidance reinforces the fear and creates repeated patterns of thoughts and feelings when we're scared.

4. **Strong Neural Pathways**: These patterns become very strong neural pathways through a process called myelination. The connection between neurons becomes so strong that there's no delay—the response seems automatic.

**[Neuroplasticity and Rewiring](#)**

The good news is that habituation creates these strong neural networks, but we can change them. We have neuroplasticity—our brains change throughout our lifetime—and we can begin to rewire the associations we make with certain situations. We can rewire our brains not to have the fear response once we are fully convinced it's unnecessary.

**[Our Negativity Bias](#)**

Another innate aspect of our brain is our negativity bias, well-proven by research. This aligns with our brain's primary function of ensuring survival. Our brain pays significantly more attention to negative things than to positive ones. This can impact and almost ruin our happiness, but it explains why we might spend so much time watching negative news, focusing on difficult situations, or engaging in conversations about how horrible everything is.

If you haven't seen my free webinar, "Rewire Your Brain for Joy and Confidence," I explore these concepts in more detail, explaining how to lower anxiety and increase joy by rewiring neural networks.

**[Our Discomfort with Uncertainty](#)**

Our brains also strongly dislike uncertainty. This contributes to anxiety because we want to ensure everything works the way we want. If you're running from a tiger, you definitely want your escape to work, but that scenario is very short-lived—it either works or it doesn't. The antelope has no real memory or projection bringing that experience forward.

In a delayed return environment, there is enormous uncertainty because we plan for things that are days, weeks, or years in the future. Many things can change in that time. Because our brain excels at creating stories, we want to anticipate every possible problem, develop solutions for things that haven't happened yet, and think of every possibility rather than focusing on acceptance of uncertainty and present action.

Having our neocortex work for us means asking: "What can I do now to improve the future? What productive action can I take today?" It still works toward a goal and considers potential problems, but focuses on our best present action.

**[Skills Needed for Different Environments](#)**

The skills needed in delayed versus immediate return environments differ significantly:

**In a delayed return environment, we need:**
- Adaptability and emotional regulation
- Impulse control
- Ability to delay gratification
- Problem-solving capabilities

Problem-solving works best when our whole brain is online, integrating emotions, memories, understanding of the present, and view of the future. If our amygdala takes over and puts us in fight-flight-freeze mode, problem-solving becomes less productive. Effective problem-solving requires creativity, critical thinking, and decision-making.

**In an immediate return environment, we need:**
- Hypervigilance
- Situational awareness
- Awareness of everything around us with a sense of urgency
- Quick reactions

If you grew up in a home with frequent crises, you likely developed these immediate return skills. When crisis occurs, you learn to suppress your own needs, jump into action, and react immediately. Consider a parent whose 2-year-old is running toward a hot stove with a pot about to fall—there's no time to think and plan. You need an immediate reaction: grab the child. Similarly, if a non-swimming child falls into a pool, immediate action is required.

The immediate return environment requires the part of our brain best suited to keeping us safe in that context. Growing up in that atmosphere habituates us to use immediate return skills constantly.

**[How to Strengthen Delayed Return Skills](#)**

Learning to strengthen delayed return skills involves:

1. **Emotional regulation** – Learn diaphragmatic breathing and how to tell your body that what it's responding to isn't real. You can think about concerns without triggering stress chemicals.

2. **Faith in your adaptability** – Recognize your ability to adapt. Humans are generally adaptable, and you likely have many examples of your own adaptability. Strengthen your connection to this adaptability and learn to value it. When we trust our ability to adapt to different situations, we significantly reduce anxiety.

**[Why Understanding This Helps](#)**

Understanding the difference between immediate and delayed return environments and how our brains evolved is empowering for several reasons:

1. It highlights the disconnect between our genuine worries and the fact that we don't need to produce anxiety chemicals. We can separate real-life challenges from our body's chemical responses through emotional regulation.

2. This theory validates that our distress is real. The distress we feel with anxiety is genuine—we experience physical reactions that feel terrible and can make us panic about our survival. But these reactions stem from ancient brain mechanisms—it's not your fault.

3. Examining your personal experiences helps you understand how your brain's evolution combined with your specific experiences to wire your brain in particular ways. You connect certain situations, experiences, and people with fear, creating automatic, habituated fear and anxiety responses.

Over time, the human brain has changed. As we grow, our brain changes, and we can take deliberate actions to help rewire it. Intentional efforts to change our thinking, responses, and behaviors can actually alter the neuronal structure of our brain.

I hope this information helps you understand your anxiety better and gives you tools to address it. Subscribe to my channel for more content like this, and tune in next week when I'll address two separate aspects of anxiety: cognitive thought patterns and somatic bodily sensations.

What aspects of the delayed versus immediate return environment do you find most helpful in understanding your own anxiety? I'd love to hear your thoughts in the comments below.
Blog Author: Barbara Heffernan, LCSW, MBA. Barbara is a licensed psychotherapist and specialist in anxiety, trauma, and healthy boundaries. She had a private practice in Connecticut for twenty years before starting her popular YouTube channel designed to help people around the world live a more joyful life. Barbara has a BA from Yale University, an MBA from Columbia University and an MSW from SCSU.  More info on Barbara can be found on her bio page.

Share this with someone who can benefit from this blog!

By Barbara Heffernan September 11, 2026
Anticipatory anxiety shuts down our creative problem-solving, just when we need it the most. Here's the process to get it back. 4 steps to help anticipatory anxiety.
By Barbara Heffernan August 6, 2026
"Just stop thinking about it" doesn't work. However, the Attention Training Technique from Metacognitive Therapy has been shown to help lower anxiety and rumination.
By Barbara Heffernan July 23, 2026
Does your brain drive you nuts going over and over the same thing—the mistake you made, the difficult conversation you had....anything you are worried about? This is rumination and it is driven by the Default Mode Network of the brain. Understanding this can help you change.
By Barbara Heffernan July 16, 2026
Social anxiety often has a trauma root — understanding the connection can help you heal.
By Barbara Heffernan July 9, 2026
Overloaded and Overwhelmed? You are in the right place. Here's help.
By Barbara Heffernan June 26, 2026
overwhelm has a cruel side effect. It shuts us down. Right when we feel like we need to get more done, not less, overwhelm makes our mind go blank or puts us into a freeze stateUnderstanding how overwhelm manifests for you can really help you calm it down.
By Barbara Heffernan June 12, 2026
Terrified to make eye contact? Constantly worried about what others think of you? You're not alone. These experiences are fairly common and often point to social anxiety disorder, which IS treatable. This blog explains this connection, provides treatment options and 3 self-help tools.
By Barbara Heffernan June 4, 2026
Interoceptive exposure can be transformative for people with somatic anxiety, specifically panic attacks, PTSD, OCD and health anxiety. Interoceptive exposure is a technique used within CBT, Cognitive Behavioral Therapy.
By Barbara Heffernan May 29, 2026
If you view your emotions as something to be avoided, squashed or feared — you are activating your your amygdala, and setting off internal alarm bells. This makes everything worse. Research has shown there are six beliefs that drive emotional dysregulation. Which one is yours?
By Barbara Heffernan May 18, 2026
Emotional distress : its intensity and duration is driven by certain beliefs. Learn 3 tools to help regulate your emotions. This has substantial research behind it – and an expert explains.