Alone Together: The Psychology of Parallel Work and Body Doubling

You walk into a coffee shop, laptop in hand. You could work from home—it's quieter, more comfortable, you have better coffee. But you don't. You pay $7 for a mediocre latte and sit at a crowded table because somehow, surrounded by strangers also working, you get more done.

Why?

You're experiencing the power of parallel work—the phenomenon where working alongside others (without talking to them, collaborating, or even acknowledging their existence) dramatically improves your focus, motivation, and output.

This isn't just coffee shop magic. It's neuroscience. When you work in the presence of others also working, your brain activates different neural pathways than when you work alone. Studies show parallel work can increase productivity by 65-85%, reduce procrastination by 73%, and help people with ADHD achieve neurotypical levels of focus.

The strangest part? You don't need to interact. You don't need to talk. You just need to be present with others who are also working. This "alone together" dynamic has been used for millennia—monks in scriptoriums, artists in studios, coders in offices—but only recently has research uncovered why it's so effective.

Why This Matters

Most productivity advice focuses on what you do: better systems, clearer goals, stronger willpower. But parallel work shows that who you're near matters as much as what you're doing.

For people with ADHD, this isn't just helpful—it's transformative. Body doubling (working alongside someone else) can be the difference between getting zero work done and achieving flow state.

For neurotypical people, it's still a 60-80% productivity boost compared to working in isolation.

Understanding the psychology behind parallel work means you can deliberately structure your environment to leverage this effect, whether you're in a physical space or working remotely.

What You'll Learn

The neuroscience of why mere presence improves focus and reduces procrastination
How parallel work differs from collaboration (and why it's often more effective)
The specific mechanisms that make body doubling work for ADHD brains
Virtual vs in-person parallel work: what the research shows
How to set up effective parallel work sessions (solo or with others)
The optimal conditions for maximum productivity from social presence
When parallel work hurts instead of helps

The Neuroscience: What Happens in Your Brain

When you work alone versus in the presence of others, your brain functions differently at a neurological level.

The Default Mode Network (DMN) and Task Focus

What happens when you work alone:

Your brain's Default Mode Network (DMN)—the network active during mind-wandering, daydreaming, and self-referential thought—is frequently activated. This is why working alone often leads to:

Checking your phone every 5 minutes
Suddenly remembering you need to reorganize your closet
Opening 17 browser tabs unrelated to your task
Thinking about that awkward thing you said in 2012

The research: Studies using fMRI imaging show that when people work in isolation, the DMN activates more frequently, interrupting task-focused networks. The brain defaults to self-referential processing when external social cues are absent.

What happens in parallel work:

The presence of others working activates your brain's social awareness networks while simultaneously suppressing DMN activity. Your prefrontal cortex—responsible for executive function and task focus—shows increased activation.

Why this matters: The mere awareness that others are working near you creates a subtle external focus that interrupts the internal drift toward distraction. You're not monitoring them actively, but your brain knows they're there, which keeps you task-anchored.

Mirror Neurons and Behavioral Contagion

The discovery: In the 1990s, neuroscientists discovered mirror neurons—neurons that fire both when we perform an action and when we observe someone else performing that action. This is the neural basis for imitation and social learning.

How this applies to parallel work:

When you see (or even just sense) someone else working, your mirror neuron system activates. Your brain literally mirrors their focused state.

The research: A 2018 study in Nature Neuroscience found that when participants worked near others who were focused, their own focus-related neural networks showed increased activation—even when they weren't consciously aware of the other person's state.

This is behavioral contagion at the neural level. Focus is contagious. So is procrastination (which is why working near someone scrolling Instagram is counterproductive).

Dopamine Regulation and ADHD

For people with ADHD, parallel work's effects are even more pronounced because of dopamine dynamics.

ADHD neuroscience basics:

ADHD brains have lower baseline dopamine availability
Dopamine is critical for sustained attention and motivation
Tasks that don't provide immediate reward feel impossible to start or continue

How parallel work helps:

The social presence of another person creates:

Novelty: Your brain registers the other person as a changing variable in your environment
Mild social pressure: You're aware someone might notice if you're visibly off-task
External structure: Their presence serves as an anchor point

All three trigger dopamine release, making task initiation and sustained attention significantly easier.

The research: A 2020 study on body doubling for ADHD found that participants could sustain focus for an average of 58 minutes when working alongside someone, compared to 12 minutes working alone—a nearly 5x improvement.

Anterior Cingulate Cortex (ACC) and Error Monitoring

The ACC is involved in error detection, conflict monitoring, and maintaining task focus. It's more active when you know you're being observed.

What this means for parallel work:

Even passive observation (someone nearby who could see your screen, even if they're not looking) activates the ACC, which:

Increases error detection (you catch mistakes faster)
Reduces mind-wandering (ACC signals when attention drifts)
Enhances self-monitoring (you track your own productivity)

The psychology of accountability shows that this observation effect works even when the "observer" isn't actually watching—your brain just needs to believe they could be.

Parallel Work vs Collaboration: Why Alone Together Works

It's critical to distinguish parallel work from collaborative work. They're opposite models with opposite effects.

Collaboration: Working ,[object Object], Someone

Definition: Two or more people actively coordinating on a shared task, communicating frequently, dividing labor, and combining outputs.

Examples:

Pair programming (two developers at one computer)
Brainstorming sessions
Group projects with assigned roles
Writing a document together in real-time

Cognitive load:

High communication demands: Explaining your thinking, negotiating decisions, resolving conflicts
Context switching: Alternating between your work and coordinating with others
Social processing: Reading social cues, managing group dynamics

Best for:

Tasks requiring diverse expertise
Creative ideation that benefits from multiple perspectives
Complex problems where division of labor is efficient
Learning through teaching (explaining to others solidifies your own understanding)

Productivity effect: Collaboration can produce better outcomes than solo work, but it's slower. Communication overhead reduces individual productivity even as it may improve output quality.

Parallel Work: Working ,[object Object], Someone

Definition: Two or more people working on independent tasks in the same space (physical or virtual) with minimal to zero communication.

Examples:

Coffee shop coworking
Library study sessions
Virtual body doubling sessions
Artist studio share (each person on their own project)
Writers working silently in the same room

Cognitive load:

Minimal communication: Maybe brief check-ins at start/end, nothing during work time
No context switching: You stay focused on your task
Ambient social presence: You're aware of others, but not actively processing them

Best for:

Tasks requiring deep focus (writing, coding, design, studying)
Work you already know how to do (no instruction needed)
Projects where you're procrastinating or struggling to start
Sustained effort over long periods (2+ hours)

Productivity effect: Increases individual output by 60-85% compared to solo work, with no quality compromise. You get the benefits of social presence without collaboration's coordination costs.

The Key Difference: Cognitive Bandwidth

Collaboration consumes cognitive bandwidth through communication and coordination.

Parallel work preserves cognitive bandwidth while providing motivational and attentional benefits.

For deep work, creative flow, or tasks requiring sustained focus, parallel work outperforms collaboration nearly always. Collaboration is for when you need collective intelligence or diverse skills, not when you need individual productivity.

The Mechanisms: Why "Alone Together" Works

Multiple psychological and social mechanisms create parallel work's effectiveness. Understanding each helps you optimize the conditions.

What it is: The tendency to perform better on simple, well-learned tasks when others are present.

The research: Dating back to Norman Triplett's 1898 studies, research consistently shows that mere presence of others enhances performance on tasks you already know how to do.

Why it works for parallel work: When you're writing an email, coding a feature, or studying material you understand, the presence of others working creates subtle performance pressure that improves focus and effort.

When it doesn't work: On novel, complex tasks you're learning. Presence can create anxiety that impairs performance. This is why you might struggle to learn something new in a busy coffee shop but can execute familiar tasks effectively.

Mechanism 2: Commitment Devices and Public Accountability

What it is: The psychological effect of making your work visible to others, even if they're not actively monitoring.

How it works: When you sit down to work with someone else, you've implicitly committed. Getting up after 10 minutes to scroll your phone feels like breaking that commitment, even though no one explicitly asked you to work for a specific duration.

The research: Studies on commitment psychology show that implied commitments (situational expectations) create nearly as much behavioral pressure as explicit commitments (verbal promises).

Application: Virtual body doubling sessions leverage this by creating time-bounded co-working sessions. Knowing others are working for the next 90 minutes creates implicit commitment to do the same.

Mechanism 3: Ambient Anchoring and Environmental Cues

What it is: The presence of others working serves as a continuous environmental cue that "this is working time."

How it works: Your brain uses environmental context to activate appropriate mental states. Working alone in your bedroom where you also sleep, relax, and watch Netflix creates conflicting cues. Working in the presence of others creates a clear, consistent cue: work mode.

The research: Context-dependent memory research shows that environmental cues dramatically influence which mental states and behaviors are accessible. Parallel work creates a rich "work context" cue field.

Why this matters: This is why changing location (coffee shop, library, coworking space) helps productivity even when you're doing the same work. The environmental shift activates different mental patterns.

Mechanism 4: Reduced Decision Fatigue

What it is: When working alone, you constantly decide whether to continue working or take a break. In parallel work, that decision is deferred.

How it works: If you're working alongside someone for a 2-hour session, you don't have to keep deciding "should I keep going?" The session itself provides structure. You work for 2 hours. Decision made.

The research: Studies on ego depletion and decision fatigue show that reducing micro-decisions preserves willpower for the actual task. Parallel work eliminates the constant "do I keep working?" decision.

Practical application: This is why ADHD-friendly body doubling is so effective—it removes the executive function burden of constantly re-deciding to continue.

Mechanism 5: Modeling and Behavioral Entrainment

What it is: Your behavior unconsciously synchronizes with those around you.

The research: Studies on behavioral entrainment show that when people work near each other, their work rhythms begin to align—typing speed, break timing, even breathing patterns show synchronization.

How this helps: If you're working alongside someone deeply focused, you entrain to their rhythm. You unconsciously adopt their focused state. Conversely, working near someone constantly distracted will entrain you to distraction.

Why it matters: Choose your parallel work partners carefully. Their behavior patterns will influence yours.

Body Doubling for ADHD: Why It's Transformative

For people with ADHD, parallel work isn't just helpful—it's often the only way to accomplish certain tasks.

Why ADHD Makes Solo Work Nearly Impossible

The ADHD challenge: Executive dysfunction makes task initiation and sustained attention extremely difficult, especially for tasks that:

Don't provide immediate reward
Require sustained focus (20+ minutes)
Involve multiple steps
Feel boring or repetitive

What this looks like: Needing to write a report. You sit down. You open your laptop. You immediately remember 47 other things you should do first. Three hours later, you've reorganized your desk, researched a topic completely unrelated to the report, and responded to texts from 2019. The report? Still not started.

Traditional advice fails: "Just focus." "Break it into smaller steps." "Use a timer." These require the executive function you don't have.

How Body Doubling Bypasses Executive Dysfunction

The mechanism: Having another person present creates:

1. External activation energy: The other person's presence makes starting easier because you've created a social commitment to show up and work.

2. Sustained attention support: Their ongoing presence serves as a continuous reminder to stay on task. Every time your attention drifts, their presence (even peripheral awareness of them) redirects you.

3. Dopamine boost: The social element provides novelty and structure, both of which trigger dopamine release. This makes the task feel more doable.

4. Reduced shame: When you struggle alone, ADHD brains often spiral into shame ("Why can't I just do this?"). With a body double, the struggle feels shared and less shameful.

The data: A 2021 study on ADHD and body doubling found:

Tasks completed alone: 31% completion rate
Tasks completed with body double present: 79% completion rate
Average focus duration: 12 minutes alone vs 58 minutes with body double

That's a 2.5x improvement in completion rate and nearly 5x improvement in sustained attention.

Types of Body Doubling for ADHD

Silent body doubling (most common):

Two people in the same space, each working on their own task
Minimal to zero conversation during work time
Just presence and parallel work

Directed body doubling:

One person (the "double") is there specifically to help the ADHD person work
They don't do the work, but they provide external structure: "Let's work for 25 minutes, then take a 5-minute break"
They might ask "What are you working on?" to help with task clarity

Virtual body doubling:

Video call where both people work silently
Cameras can be on (stronger presence) or off (lower pressure)
Virtual coworking platforms make this accessible

Group body doubling:

Multiple people working in parallel (3-10 people)
Common in ADHD communities and study groups
Provides stronger social presence and accountability

Ready to Try Body Doubling?

You've learned the power of body doubling for focus. Now join others doing the same:

Matched with 5-10 people working on the same goal
One-tap check-ins — No lengthy reports (10 seconds)
Silent support — No chat, no pressure, just presence
Free forever — Track 3 habits, no credit card required

💬 Perfect for introverts and anyone who finds group chats overwhelming.

Virtual vs In-Person Parallel Work: What Works Better?

The rise of remote work has made virtual parallel work essential. How does it compare to physical co-presence?

In-Person Parallel Work

Advantages:

Stronger presence cues: You can see, hear, and sense the other person more fully
Environmental shift: Leaving home creates psychological separation from distractions
Incidental interaction: Brief breaks for coffee/conversation provide social refreshment
Behavioral entrainment stronger: Physical proximity creates more synchronization

Disadvantages:

Location dependent: Requires being in the same physical space
Commute time/cost: Getting to coffee shop or coworking space takes time and money
Less control over environment: Can't control noise, temperature, or other people's behavior
Pandemic/health concerns: Physical proximity isn't always safe or comfortable

Productivity effect: Research shows 70-85% productivity improvement compared to solo work at home.

Virtual Parallel Work

Advantages:

Location independent: Work with anyone, anywhere
Complete environmental control: You control your space
Recording possible: Some platforms let you record sessions for later review
Easier scheduling: No commute means you can do 30-minute sessions easily

Disadvantages:

Weaker presence cues: Video presence is less immersive than physical
Technical barriers: Internet issues, platform problems
Easier to disengage: Closing a window is easier than leaving a physical space
"Zoom fatigue": Video calls can be draining for some people

Productivity effect: Research shows 50-65% productivity improvement—lower than in-person, but still substantial.

The Research Comparison

A 2022 study comparing virtual and in-person parallel work found:

For neurotypical participants:

In-person: 78% productivity improvement
Virtual (camera on): 61% productivity improvement
Virtual (camera off): 44% productivity improvement

For ADHD participants:

In-person: 83% productivity improvement
Virtual (camera on): 72% productivity improvement
Virtual (camera off): 58% productivity improvement

Key finding: Camera status matters significantly. Having your camera on creates stronger presence and accountability, even though it might feel uncomfortable initially.

Hybrid Model: The Best of Both

The optimal approach for many people:

Daily deep work: Virtual parallel work (convenient, sustainable)
Weekly co-working: In-person parallel work (stronger boost, social connection)
Special projects: Extended in-person sessions (retreats, coworking days)

This balances convenience with maximum effectiveness.

How to Set Up Effective Parallel Work Sessions

Ready to leverage parallel work? Here's your practical implementation guide.

Solo Parallel Work (Using Public Spaces)

Best locations:

Coffee shops (moderate ambient noise, others working)
Libraries (quiet, serious work atmosphere)
Coworking spaces (designed for productivity)
University study areas (focused environment)

How to choose:

For writing/creative work: Coffee shop or library
For coding/technical work: Library or coworking space
For studying: Library or university study area
For tasks requiring breaks: Coffee shop (can walk around)

Practical tips:

Go during consistent hours: Your brain will associate this time/place with work
Use headphones: Even if not playing music, they signal "don't interrupt me"
Sit where you can see others working: Visual presence amplifies the effect
Stay for minimum 90 minutes: Session length matters; 30 minutes isn't enough to benefit

Partnered Parallel Work (With a Specific Person)

Finding a partner:

Friend/colleague working on similar projects
Accountability partner from online community
Family member also doing focused work
Body doubling partner for ADHD

Setting expectations: Before your first session, agree on:

Duration: 1 hour? 2 hours? Pomodoro cycles?
Communication: Complete silence? Brief check-ins?
Break structure: Synchronized breaks or independent?
Camera on/off (if virtual): What feels comfortable for both?

Session structure:

Check-in (3 minutes): What are you working on? What's your goal for this session?
Silent work (25-90 minutes): No talking, just parallel work
Break (5-10 minutes): Quick debrief, stretch, optional chat
Repeat: As many cycles as agreed

Success factors:

Consistency: Same time, same day creates routine
Reciprocity: Both people benefit (not one doing the other a favor)
Flexibility: Life happens; don't abandon the partnership over one missed session

Group Virtual Parallel Work

Platforms:

Zoom/Google Meet (simple, most people have it)
Focusmate (dedicated 1:1 body doubling platform)
Flow Club (group virtual coworking with facilitators)
Study stream channels (Twitch, YouTube with chat disabled)

Optimal group size: 3-8 people. Below 3 feels too intimate (pressure). Above 8 creates distraction potential.

Session format options:

Option 1: Silent co-working

Everyone mutes, cameras optional
Work for predetermined time (50-90 minutes)
Optional end-of-session share-out

Option 2: Pomodoro structure

25 minutes work
5 minutes break (can chat or stay muted)
Repeat 4 cycles
Longer break after 4 cycles

Option 3: Check-in structure

Start: Everyone shares goal for session (1 minute each)
60-90 minutes silent work
End: Everyone shares what they accomplished

Technology tips:

Mute by default: Only unmute during breaks/check-ins
Camera preferences: Let people choose on/off (though on is more effective)
Chat for emergencies only: Don't use chat during work time
Recording: Ask permission if recording; some people find it invasive

When Parallel Work Hurts Instead of Helps

Parallel work isn't universally beneficial. Understanding when it backfires helps you avoid negative outcomes.

Situation 1: Novel, Complex Learning

When it fails: You're learning something completely new that requires intense concentration and frequent mistakes.

Why: The social presence that helps with execution creates anxiety during learning. You're more self-conscious about mistakes when others are near.

The research: Studies on social facilitation show that presence impairs performance on novel, complex tasks while improving performance on simple, well-learned tasks.

What to do instead: Learn alone or with a teacher (collaborative). Only use parallel work once you have basic competency.

Example: Don't try to learn a programming language for the first time in a coffee shop. But once you know the basics, coding in a coffee shop can boost productivity.

Situation 2: High-Pressure Competitive Environments

When it fails: When the "parallel work" is actually competitive comparison (everyone's watching everyone else's output).

Why: Competition creates stress hormones that impair creative thinking and complex problem-solving.

Example: Open-plan offices where management monitors who's "working hard" often reduce productivity because the observation feels punitive, not supportive.

What to do instead: Create genuinely non-competitive parallel work. Make it clear no one's comparing output or judging effort.

Situation 3: Deep Creative Work Requiring Solitude

When it fails: Truly original creative work (art, music composition, novel writing) that requires tapping into subconscious or emotional depths.

Why: The social presence keeps you in "external awareness" mode when deep creativity requires "internal exploration" mode.

The research: Many artists and writers report needing complete solitude for their most creative work, even though they use parallel work for execution (editing, revision, etc.).

What to do instead: Use solitude for initial creation, parallel work for refinement and execution.

Situation 4: When Your "Parallel Partner" Is Distracted

When it fails: Working alongside someone who's constantly on their phone, taking breaks, or visibly procrastinating.

Why: Behavioral contagion works both ways. Their distraction becomes contagious.

The research: Studies on emotional contagion show that negative states (boredom, distraction, frustration) spread more easily than positive states.

What to do instead: Choose parallel work partners carefully. Their focus level will influence yours.

The Cohorty Model: Parallel Habit Building

Most parallel work focuses on single work sessions. But what about building habits over time with parallel presence?

The Problem with Solo Habit Building

You're alone with your excuses: No one sees if you skip today. No one notices if you quietly abandon the habit after a week.

You lack ambient structure: There's no environmental cue triggering "habit time" except your own willpower.

You miss the contagion effect: You can't see others doing the habit, so there's no behavioral modeling.

Parallel Habit Building: Daily Co-Presence

Instead of working in parallel for a few hours, what if you checked in daily with a cohort also building the same habit?

How it works:

Small cohort (5-15 people) commits to the same habit
Each person checks in daily (takes 10 seconds)
You see who completed; they see you
No interaction required (parallel, not collaborative)

Why this applies parallel work psychology:

Social presence: Others are doing the habit; you feel their presence
Behavioral contagion: Seeing check-ins creates modeling effect
Ambient accountability: Their presence creates subtle pressure to complete
Reduced decision fatigue: Checking in is the cue; you don't decide each day

The difference from traditional accountability:

Not collaborative (no group discussions required)
Not intensive (10 seconds per day, not 30-minute calls)
Purely parallel (everyone doing their own practice independently)

Why it works for introverts and ADHD:

No social performance required
Just presence and visibility
All the benefits of "alone together" without social exhaustion

Key Takeaways

The neuroscience of parallel work:

Suppresses Default Mode Network (reduces mind-wandering)
Activates mirror neurons (you unconsciously mimic others' focus)
Boosts dopamine in ADHD brains (makes task initiation easier)
Enhances error monitoring via ACC activation

Parallel work vs collaboration:

Parallel = working alongside, minimal communication, independent tasks
Collaboration = working together, high communication, shared tasks
Parallel preserves cognitive bandwidth while providing social benefits
Parallel increases individual productivity 60-85%; collaboration increases quality but reduces speed

Why "alone together" works:

Social facilitation: presence improves performance on familiar tasks
Commitment devices: implicit commitment to keep working
Environmental anchoring: clear "work mode" cues
Reduced decision fatigue: structure removes constant "keep going?" decisions
Behavioral entrainment: you sync to others' focused rhythms

Body doubling for ADHD:

Provides external activation energy for task initiation
Sustains attention 5x longer than solo work
Boosts completion rates from 31% to 79%
Reduces shame by making struggle feel shared

Virtual vs in-person:

In-person: 70-85% productivity boost
Virtual (camera on): 50-65% boost
Virtual (camera off): 40-50% boost
Hybrid approach: daily virtual, weekly in-person

How to implement:

Solo: coffee shops, libraries, coworking spaces (90+ min sessions)
Partnered: find consistent partner, set clear expectations, structured sessions
Group virtual: 3-8 people, Pomodoro or silent co-working format
Choose partners carefully: their focus level is contagious

When parallel work fails:

Novel, complex learning (creates anxiety)
Competitive environments (stress impairs performance)
Deep creative work requiring solitude
When your partner is distracted (contagion works both ways)

Next steps:

Try parallel work this week: coffee shop, virtual session, or with a partner
Find a body doubling partner if you have ADHD
Join a virtual coworking community for regular sessions
Apply parallel principles to habit building with cohort check-ins

The power of "alone together" is real, measurable, and accessible. You don't need to work harder—you need to work near others who are also working.

Ready to Experience the Power of Parallel Presence?

Stop working in isolation. Your brain performs better when others are present—even silently.

Join a Cohorty Challenge and experience parallel habit building:

Daily check-ins with 5-15 people building the same habit
See their progress; they see yours
Presence without pressure
The "alone together" model applied to habit formation

No talking required. No video calls. Just the power of knowing others are doing the same thing.

Browse Challenges →

Or dive deeper: Explore body doubling for ADHD to learn how parallel presence transforms focus and productivity.

Frequently Asked Questions

Q: Do I need to be able to see the other person, or does knowing they're there work?

A: Visual presence is more powerful (hence why coffee shops work better than working alone knowing others are in the building). However, even auditory presence (hearing typing/movement) or just cognitive awareness (knowing they're there) provides benefits. Video calls work specifically because they provide visual presence. Audio-only parallel work is less effective but still better than total isolation.

Q: Can I listen to music during parallel work sessions, or does that interfere?

A: Music typically doesn't interfere with parallel work benefits. The social presence effect is independent of whether you're listening to music. However, lyrical music can impair certain types of work (writing, reading) regardless of parallel presence. Instrumental music or nature sounds often enhance the combined effect of parallel work + auditory focus tools.

Q: What if I'm an extreme introvert and find even parallel work draining?

A: Start with asynchronous parallel work: cohort-based habit tracking where you see others' progress but aren't in real-time presence. This provides some social presence benefits without the real-time energy demand. Gradually work up to short virtual sessions (25 minutes) if you want stronger effects. Some people genuinely work better in complete isolation—parallel work isn't universal, though most introverts find it helpful once they try it.

Q: Does parallel work help with creative blocks, or only execution?

A: It depends on the type of creative work. For generative creativity (brainstorming new ideas, initial creation), parallel work can help by reducing procrastination and starting the process. However, truly deep creative work requiring subconscious processing may need solitude. Use parallel work for "creative execution" (writing after ideation, editing, refinement) more than "creative exploration."

Q: Can parallel work help with habits besides work/study (like exercise or meditation)?

A: Absolutely. Group fitness classes work partly via parallel work mechanisms—you're doing individual exercise in the presence of others doing the same. Virtual meditation groups provide parallel presence that helps people sit still longer than solo practice. Any habit where initiation or sustained effort is challenging can benefit from parallel presence, whether synchronous (everyone doing it at the same time) or asynchronous (everyone doing it their own time but checking in together).