diff --git a/app/controllers/affinities_controller.rb b/app/controllers/affinities_controller.rb
index 097e051..f8cb9cb 100644
--- a/app/controllers/affinities_controller.rb
+++ b/app/controllers/affinities_controller.rb
@@ -3,7 +3,7 @@
 # frozen_string_literal: true
 
 class AffinitiesController < ApplicationController
-  before_action :set_group
+  before_action :set_group, except: :reset
 
   def index
     overridden = @group.affinities.each_with_object({}) do |affinity, acc|
@@ -39,6 +39,20 @@ class AffinitiesController < ApplicationController
     end
   end
 
+  def reset
+    affinities = Group.pluck(:id).combination(2).map do |(group_a_id, group_b_id)|
+      {
+        group_a_id:,
+        group_b_id:,
+        discomfort: Tables::DiscomfortCalculator.cohesion_discomfort(id_a: group_a_id, id_b: group_b_id).to_f
+      }
+    end
+
+    GroupAffinity.upsert_all(affinities)
+
+    render json: {}, status: :ok
+  end
+
   private
 
   def for_each_group
diff --git a/config/routes.rb b/config/routes.rb
index b87e0a0..10c45ae 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -24,6 +24,7 @@ Rails.application.routes.draw do
     end
 
     resources :groups, only: %i[index create update destroy] do
+      post 'affinities/reset', to: 'affinities#reset', on: :collection
       resources :affinities, only: %i[index] do
         put :bulk_update, on: :collection
         get :default, on: :collection
diff --git a/spec/requests/affinities_spec.rb b/spec/requests/affinities_spec.rb
index e458abb..a236160 100644
--- a/spec/requests/affinities_spec.rb
+++ b/spec/requests/affinities_spec.rb
@@ -5,6 +5,17 @@
 require 'swagger_helper'
 
 RSpec.describe 'affinities' do
+  path '/{slug}/groups/affinities/reset' do
+    parameter Swagger::Schema::SLUG
+
+    post('reset affinities') do
+      tags 'Affinities'
+      description 'Reset all affinities to default values based on the distance between groups in the hierarchy.'
+
+      response_empty200
+    end
+  end
+
   path '/{slug}/groups/{group_id}/affinities' do
     parameter Swagger::Schema::SLUG
     parameter name: 'group_id', in: :path, type: :string, format: :uuid, description: 'group_id'